There is little evidence that any one antihistamine is superior to another, and patients vary considerably in their response to them. The antihistamines di?er in their duration of action and in the incidence of side-effects such as drowsiness. Most are short-acting, but some (such as promethazine) work for up to 12 hours. They all cause sedation but promethazine, trimeprazine and dimenhydrinate tend to be more sedating while chlorpheniramine and cyclizine are less so, as are astemizole, oxatomide and terfenadine. Patients should be warned that their ability to drive or operate machinery may be impaired when taking these drugs, and that the effects of ALCOHOL may be increased.... antihistamine drugs
The most widely prescribed type of antidepressants are the tricyclics, so-called because their molecular structure includes three rings. The other commonly used types are named after the actions they have on chemicals in the brain: the SELECTIVE SEROTONIN-REUPTAKE INHIBITORS (SSRIS) and the MONOAMINE OXIDASE INHIBITORS (MAOIS) – see also below. All types of antidepressant work in similar ways. Tricyclic antidepressants have cured depression in millions of people, but they can cause unpleasant side-effects, particularly in the ?rst couple of weeks. These include SEDATION, dry mouth, excessive sweating, CONSTIPATION, urinary problems, and impotence (inability to get an erection). Up to half of all people prescribed tricyclic drugs cannot tolerate the side-effects and stop treatment before their depression is properly treated. More seriously, tricyclics can upset the rhythm of the heart in susceptible people and should never be given in the presence of heart disease.
The SSRIs are newer, coming into wide use in the late 1980s. They increase the levels in the brain of the chemical messenger SEROTONIN, which is thought to be depleted in depression. Indeed, the SSRIs are as e?ective as tricyclics and, although they can cause nausea and excessive sweating at ?rst, they generally have fewer side-effects. Their main disadvantage, however, is that they cost much more than the most commonly used tricyclic, amitriptyline. On the other hand, they are more acceptable to many patients and they cause fewer drop-outs from treatment – up to a quarter rather than a half. The money saved by completed, successful treatment may outweigh the prescribing costs. SSRIs have been reported as associated with an increased risk of suicide.
Another group of antidepressants, the MAOIs, have been in use since the late 1950s.
They are stimulants, rather than sedatives, and are particularly helpful for people who are physically and mentally slowed by depression. They work well but have one big disadvantage – a dangerous interaction with certain foods and other drugs, causing a sudden and very dangerous increase in blood pressure. People taking them must carry an information card explaining the risk and listing the things that they should avoid. Because of this risk, MAOIs are not used much now, except when other treatments have failed. A new MAOI, moclobemide, which is less likely to interact and so cause high blood pressure, is now available.
LITHIUM CARBONATE is a powerful antidepressant used for intractable depression. It should be used under specialist supervision as the gap between an e?ective dose and a toxic one is narrow.
St John’s Wort is a popular herbal remedy which may be e?ective, but which is handicapped by di?erences of strength between di?erent preparations or batches. It can interact with a number of conventional drugs and so needs to be used cautiously and with advice.
In general, antidepressants work by restoring the balance of chemicals in the brain. Improved sleep and reduced anxiety are usually the ?rst signs of improvement, particularly among people taking the more sedative tricyclic drugs. Improvement in other symptoms follow, with the mood starting to lift after about two weeks of treatment. Most people feel well by three months, although a few residual symptoms, such as slowness in the mornings, may take longer to clear up. People taking antidepressants usually want to stop them as soon as they feel better; however, the risk of relapse is high for up to a year and most doctors recommend continuing the drugs for around 4–6 months after recovery, with gradual reduction of the dose after that.
Withdrawal reactions may occur including nausea, vomiting, headache, giddiness, panic or anxiety and restlessness. The drugs should be withdrawn gradually over about a month or longer (up to six months in those who have been on maintenance treatment).
A wide range of antidepressant drugs is described in the British National Formulary. Examples include:
Tricyclics: amitryptyline, imipramine, doxepin.
MAOIs: phenelzine, isocarboxazid.
SSRIs: citalopram, ?uoxetine, paraxtene. (Antidepressant drugs not in these three
groups include ?upenthixol, mertazapine and venlafaxine.)... antidepressant drugs
The drugs used in combination are:
The receptor antagonists, which reduce the output of gastric acid by histamine H2receptor blockade; they include CIMETIDINE, FAMOTIDINE and RANITIDINE.
ANTIBIOTICS to eradicate Helicobacter pylori infection, a major cause of peptic ulceration. They are usually used in combination with one of the PROTON-PUMP INHIBITORS and include clarithomycin, amoxacillin and metronidazole.
BISMUTH chelates.
The prostaglandin analogue misoprostol has antisecretory and protective properties.
Proton-pump inhibitors omeprazole, lansoprazole, pantaprazole and rabeprazole, all of which inhibit gastric-acid secretion by blocking the proton pump enzyme system.... ulcer healing drugs
Antidiabetic drugs include insulin, which must be administered by injection, and oral hypoglycaemics such as glibenclamide and metformin. Acarbose and guar gum reduce or slow absorption of carbohydrate from the intestines after meals. Repaglinide stimulates insulin release from the pancreas for a short time and may be taken directly before meals. Rosiglitazone reduces resistance to the effects of insulin in the tissues and may be used together with other hypoglycaemics.... antidiabetic drugs
Adverse effects can be divided into types. First, those which are closely related to the concentration of the drug and accord with what is known of its PHARMACOLOGY. These so-called type A (augmented pharmacological) effects are distinguished from type B (bizarre) effects which are unpredictable, usually rare, and often severe. ANAPHYLAXIS is the most obvious of these; other examples include bone-marrow suppression with CO-TRIMOXAZOLE; hepatic failure (see HEPATITIS) with SODIUM VALPROATE; and PULMONARY FIBROSIS with AMIODARONE. A more comprehensive classi?cation includes reactions type C (chronic effects), D (delayed effects – such as teratogenesis or carcinogenesis) and E (end-of-dose effects – withdrawal effects). Examples of adverse reactions include nausea, skin eruptions, jaundice, sleepiness and headaches.
While most reported adverse reactions are minor and require no treatment, patients should remind their doctors of any drug allergy or adverse e?ect they have suffered in the past. Medical warning bracelets are easily obtained. Doctors should report adverse effects to the authorities – in the case of Britain, to the Committee on Safety of Medicines (CSM), using the yellow-card reporting machinery.... adverse reactions to drugs
They work by blocking the stimulation of beta adrenergic receptors by the neurotransmitters adrenaline and noradrenaline, which are produced at the nerve endings of that part of the SYMPATHETIC NERVOUS SYSTEM – the autonomous (involuntary) network
– which facilitates the body’s reaction to anxiety, stress and exercise – the ‘fear and ?ight’ response.
Beta1 blockers reduce the frequency and force of the heartbeat; beta2 blockers prevent vasodilation (increase in the diameter of blood vessels), thus in?uencing the patient’s blood pressure. Beta1 blockers also affect blood pressure, but the mechanism of their action is unclear. They can reduce to normal an abnormally fast heart rate so the power of the heart can be concomitantly controlled: this reduces the oxygen requirements of the heart with an advantageous knock-on e?ect on the respiratory system. These are valuable therapeutic effects in patients with ANGINA or who have had a myocardial infarction (heart attack – see HEART, DISEASES OF), or who suffer from HYPERTENSION. Beta2 blockers reduce tremors in muscles elsewhere in the body which are a feature of anxiety or the result of thyrotoxicosis (an overactive thyroid gland – see under THYROID GLAND, DISEASES OF). Noncardioselective blockers also reduce the abnormal pressure caused by the increase in the ?uid in the eyeball that characterises GLAUCOMA.
Many beta-blocking drugs are now available; minor therapeutic di?erences between them may in?uence the choice of a drug for a particular patient. Among the common drugs are:
| Primarily cardioselective | Non-cardioselective |
| Acebutolol | Labetalol |
| Atenolol | Nadolol |
| Betaxolol | Oxprenolol |
| Celiprolol | Propanolol |
| Metoprolol | Timolol |
These powerful drugs have various side-effects and should be prescribed and monitored with care. In particular, people who suffer from asthma, bronchitis or other respiratory problems may develop breathing diffculties. Long-term treatment with beta blockers should not be suddenly stopped, as this may precipitate a severe recurrence of the patient’s symptoms – including, possibly, a sharp rise in blood pressure. Gradual withdrawal of medication should mitigate untoward effects.... beta-adrenoceptor-blocking drugs
Prescriptions for drugs should be printed or written clearly in ink and signed and dated by the prescriber (computer-generated facsimile signatures do not meet legal requirements). They should include the patient’s name, address and age (obligatory for children under 12), the name of the drug to be supplied, the dose and dose frequency, and the total quantity to be supplied. Any special instructions (e.g. ‘after food’) should be stated. There are special regulations about the prescription of drugs controlled under the Misuse of Drugs Regulations 1985 (see CONTROLLED DRUGS). A pharmacist can advise about which drugs are available without prescription, and is able to recommend treatment for many minor complaints. Information about exemption from prescription charges in the NHS can be obtained from health visitors, general practitioners, or social security o?ces.... drugs
In high doses, amfetamines can cause tremor, sweating, anxiety, and sleeping problems. Delusions, hallucinations, high blood pressure, and seizures may also occur. Prolonged use may produce tolerance and drug dependence.
Amfetamines are often abused for their stimulant effect.... amfetamine drugs
The Misuse of Drugs Regulations 1985 de?ne the classes of person authorised to supply and possess controlled drugs, and lay down the conditions under which these activities may be carried out. In the Regulations, drugs are divided into ?ve schedules specifying the requirements for supply, possession, prescribing and record-keeping. Schedule I contains drugs which are not used as medicines. Schedules II and III contain drugs which are subject to the prescription requirements of the Act (see below). They are distinguished in the British National Formulary (BNF) by the symbol CD and they include morphine, diamorphine (heroin), other opioid analgesics, barbiturates, amphetamines, cocaine and diethylpropion. Schedules IV and V contain drugs such as the benzodiazepines which are subject to minimal control. A full list of the drugs in each schedule can be found in the BNF.
Prescriptions for drugs in schedules II and III must be signed and dated by the prescriber, who must give his or her address. The prescription must be in the prescriber’s own handwriting and provide the name and address of the patient and the total quantity of the preparation in both words and ?gures. The pharmacist is not allowed to dispense a controlled drug unless all the information required by law is given on the prescription.
Until 1997 the Misuse of Drugs (Noti?cation and Supply of Addicts) Regulations 1973 governed the noti?cation of addicts. This was required in respect of the following commonly used drugs: cocaine, dextromoramide, diamorphine, dipipanone, hydrocodeine, hydromorphone, levorphanol, methadone, morphine, opium, oxycodone, pethidine, phenazocine and piritranide.
In 1997 the Misuse of Drugs (Supply to Addicts) Regulations 1997 revoked the 1973 requirement for noti?cation. Doctors are now expected to report (on a standard form) cases of drug misuse to their local Drug Misuse Database (DMD). Noti?cation by the doctor should be made when a patient ?rst presents with a drug problem or when he or she visits again after a gap of six months or more. All types of misuse should be reported: this includes opioids, benzodiazepines and central nervous system stimulants. The data in the DMD are anonymised, which means that doctors cannot check on possible multiple prescribing for drug addicts.
The 1997 Regulations restrict the prescribing of diamorphine (heroin), Diconal® (a morphine-based drug) or cocaine to medical practitioners holding a special licence issued by the Home Secretary.
Fuller details about the prescription of controlled drugs are in the British National Formulary, updated twice a year, and available on the Internet (see www.bnf.org).... controlled drugs
The other dangers of administering drugs in pregnancy are the teratogenic effects (see TERATOGENESIS). It is understandable that a drug may interfere with a mechanism essential for growth and result in arrested or distorted development of the fetus and yet cause no disturbance in the adult, in whom these di?erentiation and organisation processes have ceased to be relevant. Thus the e?ect of a drug upon a fetus may di?er qualitatively as well as quantitatively from its e?ect on the mother. The susceptibility of the embryo will depend on the stage of development it has reached when the drug is given. The stage of early di?erentiation – that is, from the beginning of the third week to the end of the tenth week of pregnancy – is the time of greatest susceptibility. After this time the risk of congenital malformation from drug treatment is less, although the death of the fetus can occur at any time.... drugs in pregnancy
Aluminium may cause constipation and magnesium may cause diarrhoea; but these effects may be avoided if a preparation contains both ingredients.
Antacids interfere with the absorption of many drugs and should not be taken at the same time as other drugs.... antacid drugs
Misuse of Drugs Act 1971 This legislation forbids activities relating to the manufacture, sale and possession of particular (controlled) drugs. These are classi?ed into three grades according to their dangers if misused. Any o?ences concerning class A drugs, potentially the most damaging when abused, carry the toughest penalties, while classes B and C attract lesser penalties if abused.
Class A includes: cocaine, dextromoramide, diamorphine (heroin), lysergic acid (LSD), methadone, morphine, opium, pethidine, phencyclidine acid and injectable preparations of class B drugs.
Class B includes: oral amphetamines, barbiturates, codeine, glutethimide, marijuana (cannabis), pentazocine and pholcodine.
Class C includes: drugs related to the amphetamines, anabolic and androgenic steroids, many benzodiazepines, buprenorphine, diethyl propion, human chorionic gonadotrophin (HCG), mazindol, meprobamate, pemoline, phenbuterol, and somatropin.
Misuse of Drugs Regulations 1985 These regulations de?ne those people who are authorised in their professional capacity to supply and possess controlled drugs. They also describe the requirements for legally undertaking these activities, such as storage of the drugs and limits on their prescription.
Drugs are divided into ?ve schedules and some examples follow.
I: Almost all are prohibited except in accordance with Home O?ce authority: marijuana (cannabis), LSD.
II: High potential for abuse but have
accepted medical uses: amphetamines, cocaine.
III: Lower potential for abuse: barbiturates, meprobamate, temazepam.
IV: Lower potential for abuse than I to III. Minimal control: benzodiazepines.
V: Low potential for abuse: generally compound preparations containing small amounts of opioids: kaolin and morphine (antidiarrhoeal medicine), codeine linctus (cough suppressant).
(See also CONTROLLED DRUGS.)... misuse of drugs
The major defect in this system is the dif?culty in obtaining reports of adverse reactions. Evidence suggests that at most, about 10 per cent of such reactions are reported. One method of trying to obtain this information is the ‘yellow card’ system. It is so called because it is based on the distribution of yellow cards to all doctors, pharmacists and dentists, on which they are asked to report any adverse reaction happening to someone taking a drug, whether or not they think it is the cause. Alternatively the CSM has a Freephone line and on-line computer facilities (ADROIT) for practitioners to use. Even though the annual number of adverse reactions reported in this way has risen from around 5,000 in 1975 to more than 18,000, this is probably fewer than the number actually occurring.
Two further committees in this safety screen are the Joint Committee on Vaccination and Immunisation and the Adverse Reactions to Vaccines and Immunological Substances Committee.... safety of drugs
Excessive doses of anticoagulant drugs increase the risk of unwanted bleeding, and regular monitoring is needed.... anticoagulant drugs
Anticonvulsants may produce various side effects, including impaired memory, reduced concentration, poor coordination, and fatigue. If the side effects are severe, they can often be minimized by use of an alternative anticonvulsant.... anticonvulsant drugs
In most acute cases of diarrhoea, the only treatment recommended is oral rehydration therapy.
Antidiarrhoeal drugs include adsorbents, bulk-forming agents such as kaolin, and antimotility drugs (including the opioid drugs, morphine and codeine, and loperamide), which slow movement through the intestine.
None of these drugs are suitable for children.... antidiarrhoeal drugs
Inotropics act on beta receptors in heart muscle (see HEART), increasing its contractility and sometimes the heart rate. DOBUTAMINE and DOPAMINE are cardiac stimulants, while dopexamine acts on heart muscle and, via peripheral dopamine receptors, increases the excretion of URINE. ISOPRENALINE is used only as emergency treatment of heart block (interruption of the heart’s conduction) or severe slowing of the heart rate (bradycardia).... sympathomimetic drugs
Adverse effects are uncommon with paracetamol. Aspirin and NSAIDs may irritate the stomach lining and cause nausea, abdominal pain, and, rarely, a peptic ulcer. Nausea, drowsiness, constipation, and breathing difficulties may occur with opioid analgesics.... analgesic drugs
Androgen drugs are occasionally used to treat certain types of breast cancer. They have been widely used by sportsmen wishing to increase muscle bulk and strength, a practice that is dangerous to health (see steroids, anabolic).
Adverse effects include fluid retention, weight gain, increased blood cholesterol, and, rarely, liver damage. When taken by women, the drugs can cause male characteristics, such as facial hair, to develop.
androgen hormones A group of hormones that stimulate the development of male sexual characteristics.
Androgens are produced by specialized cells in the testes in males and in the adrenal glands in both sexes. The ovaries secrete very small quantities of androgens until the menopause. The most active androgen is testosterone, which is produced in the testes. The production of androgens by the testes is controlled by certain pituitary hormones, called gonadotrophins. Adrenal androgens are controlled by ACTH, another pituitary hormone.
Androgens stimulate male secondary sexual characteristics at puberty, such as the growth of facial hair and deepening of the voice. They have an anabolic effect (they raise the rate of protein synthesis and lower the rate at which it is broken down). This increases muscle bulk and accelerates growth. At the end of puberty, androgens cause the long bones to stop growing. They stimulate sebum secretion, which, if excessive, causes acne. In early adult life, androgens promote male-pattern baldness.
Androgen deficiency may occur if the testes are diseased or if the pituitary gland fails to secrete gonadotrophins. Typical effects include decreased body and facial hair, a high-pitched voice, underdevelopment of the genitalia, and poor muscle development.
Overproduction of androgens may be the result of adrenal disorders (see adrenal tumours; adrenal hyperplasia, congenital), of testicular tumours (see testis, cancer of), or, rarely, of androgensecreting ovarian tumours (see ovary, cancer of).
In men, excess androgens accentuate male characteristics; in boys, they cause premature sexual development.
In women, excess androgens cause virilization, the development of masculine features such as an increase in body hair, deepening of the voice, clitoral enlargement, and amenorrhoea.... androgen drugs
Antihistamine drugs and anticholinergic drugs reduce vomiting in motion sickness, vertigo, and Ménière’s disease.
The most powerful antiemetics are used to control nausea and vomiting associated with radiotherapy or anticancer drugs.
These drugs include serotonin antagonists such as ondansetron and nabilone.
Antiemetics are not normally used in the treatment of food poisoning because the body needs to rid itself of harmful substances.
Only certain antiemetics can be used to treat vomiting in early pregnancy because damage to the developing fetus may occur.
Many antiemetics cause drowsiness.... antiemetic drugs
Most of the commonly used antibiotic drugs belong to one of the following classes: penicillins, quinolones, aminoglycosides, cephalosporins, macrolides, and tetracyclines. Some antibiotics are effective against only certain types of bacteria; others, which are known as broad-spectrum antibiotics, are effective against a wide range.
Some bacteria develop resistance to a previously effective antibiotic drug. This is most likely to occur during long-term treatment. Some alternative antibiotics are available to treat bacteria that have become resistant to the more commonly prescribed drugs.
Most antibiotic drugs can cause nausea, diarrhoea, or a rash. Antibiotics may disturb the normal balance between certain types of bacteria and fungi in the body, leading to proliferation of the fungi that cause candidiasis (thrush). Some people experience a severe allergic reaction to the drugs, resulting in facial swelling, itching, or breathing difficulty.... antibiotic drugs
Most anticancer drugs are cytotoxic (kill or damage rapidly dividing cells), but some act by slowing the growth of hormone-sensitive tumours. Anticancer drugs are often prescribed in combination to maximize their effects.
Treatment with cytotoxic drugs is often given by injection in short courses repeated at intervals. Some drugs cause nausea and vomiting and may result in hair loss and increased susceptibility to infection. Others, such as tamoxifen, which is used for breast cancer, are given continuously by mouth for months or years and cause few side effects.... anticancer drugs
Anticholinergic drugs are used in the treatment of irritable bowel syndrome, urinary incontinence, Parkinson’s disease, asthma, and bradycardia (abnormally slow heartbeat).
They are also used to dilate the pupil before eye examination or surgery.
Anticholinergic drugs are used as a premedication before general anaesthesia and to treat motion sickness.
They may cause dry mouth, blurred vision, urinary retention, and confusion.... anticholinergic drugs
Antifungal preparations are available in various forms including tablets, injection, creams, and pessaries. Prolonged treatment of serious fungal infections can result in side effects that include liver or kidney damage.... antifungal drugs
Antipruritics may be applied as creams and emollients and may contain corticosteroid drugs, antihistamine drugs, or local anaesthetics.
Oral antihistamines may also be used to relieve itching.... antipruritic drugs
Antirheumatic drugs affect the disease process and may limit joint damage, unlike nonsteroidal anti-inflammatory drugs, which only relieve pain and stiffness.
The main antirheumatic drugs are corticosteroid drugs, immunosuppressant drugs, chloroquine, gold, penicillamine, and sulfasalazine.
Many of these drugs can have serious side effects, and treatment must be under specialist supervision.... antirheumatic drugs
However, antiviral drugs can reduce the severity of some viral infections (most notably herpes, influenza, viral hepatitis, and cytomegalovirus infections), particularly in people who have reduced immunity.
Advances have also been made in the treatment of infection (see antiretroviral drugs).... antiviral drugs
Minor adverse effects of benzodiazepines include daytime drowsiness, dizziness, and forgetfulness. Unsteadiness and slowed reactions may also occur. Regular users may become psychologically and physically dependent; for this reason, the drugs are usually given for courses of 2–3 weeks or less. When the drugs are stopped suddenly, withdrawal symptoms, such as anxiety, restlessness, and nightmares may occur. Benzodiazepine drugs are sometimes abused for their sedative effect.... benzodiazepine drugs
There are 2 types of beta receptor: beta 1 and beta 2. Beta 1 receptors are present in the heart and blood vessels, and beta 2 in the lungs. Some betablockers (such as acebutolol, atenolol, and metoprolol) are termed cardioselective and, because they act mostly on beta 1 receptors, are used mainly to treat heart disease such as angina, hypertension, and cardiac arrhythmia. The drugs are sometimes given after a myocardial infarction (heart attack) to reduce the likelihood of further damage to the heart muscle.
Other types of beta-blocker, such as oxprenolol, propranolol, and timolol, may be given to prevent migraine attacks by acting on blood vessels in the head; reduce the physical symptoms of anxiety; or control the symptoms of thyrotoxicosis. Beta-blocker drugs such as timolol are sometimes given in the
form of eye drops to treat glaucoma and work by lowering the fluid pressure in the eyeball.
Beta-blockers may reduce an individual’s capacity for strenuous exercise. The drugs may worsen the symptoms of asthma, bronchitis, or other forms of lung disease. They may also reduce the flow of blood to the limbs, causing cold hands and feet. In addition, sleep disturbance and depression can be side effects of beta-blockers.... beta-blocker drugs
Bisphosphonates are also used in the prevention or treatment of osteoporosis.... bisphosphonate drugs
CEPHALOSPORIUM ACREMONIUM, which are effective against a wide range of infections.
Cephalosporins are used to treat ear, throat, and respiratory tract infections, and conditions, such as urinary tract infections and gonorrhoea, in which the causative bacteria are resistant to other types of antibiotics.
Occasionally, the drugs cause allergic reactions, such as rash, itching, and fever.
Rarely, anaphylactic shock occurs.
Other side effects include diarrhoea and blood disorders.... cephalosporin drugs
They are used to treat heart conditions, most commonly atrial fibrillation.
Those most frequently used are digitoxin and digoxin.... digitalis drugs
The main side effects of sympathomimetics are palpitations and trembling.
Anticholinergics may cause dry mouth, blurred vision, and, rarely, difficulty in passing urine.
Xanthines may cause headaches, nausea and palpitations.... bronchodilator drugs
Side effects are uncommon when corticosteroids are given as a cream or by inhaler, but tablets taken in high doses for long periods may cause oedema, hypertension, diabetes mellitus, peptic ulcer, Cushing’s syndrome, inhibited growth in children, and, in rare cases, cataract or psychosis. High doses also impair the body’s immune system. Long-term treatment suppresses production of corticosteroid hormones by the adrenal glands, and sudden withdrawal may lead to adrenal failure.... corticosteroid drugs
They work by narrowing blood vessels in the membranes lining the nose.
This action reduces swelling, inflammation, and the amount of mucus produced by the lining.
Common drugs include ephedrine, oxymetazoline, and phenylephrine.
Small amounts of these drugs are present in many over-thecounter cold remedies.
Taken by mouth, decongestant drugs may cause tremor and palpitations.
Adverse effects are unlikely with nose drops, but if taken for several days they become ineffective and symptoms may then recur or worsen despite continued treatment.... decongestant drugs
Types of diuretic drug differ markedly in their speed and mode of action. Thiazide diuretics cause a moderate increase in urine production. Loop diuretics are fast-acting, powerful drugs. They are often used as an emergency treatment for heart failure. Potassium-sparing diuretics are used along with thiazide and loop diuretics, both of which may cause the body to lose too much potassium. Carbonic anhydrase inhibitors block the action of the enzyme carbonic anhydrase, which affects the amount of bicarbonate ions in the blood; these drugs increase urine output moderately but are effective only for short periods of time. Osmotic diuretics are used to maintain urine output following serious injury or major surgery.
Diuretic drugs may cause chemical imbalances in the blood.
Hypokalaemia (low blood levels of potassium) is usually treated with potassium supplements or potassium-sparing diuretic drugs.
A diet rich in potassium may be helpful.
Some diuretics raise the blood level of uric acid, increasing the risk of gout.
Certain diuretics increase the blood glucose level, which can cause or worsen diabetes mellitus.... diuretic drugs
In women, fertility drugs may be given when abnormal hormone production by the pituitary gland or ovaries disrupts ovulation or causes mucus around the cervix to become so thick that sperm cannot penetrate it. In men, fertility drugs are less effective, but they may be used when abnormal hormone production by the pituitary gland or testes interferes with sperm production. (See also clomifene; gonadotrophin hormones; testosterone.)... fertility drugs
The drugs work by suppressing the production and activity of white blood cells called lymphocytes. Side effects vary, but all the drugs increase the risk of infection and of the development of certain cancers.... immunosuppressant drugs
Keratolytic drugs, which include urea and salicylic acid preparations, are used to treat skin and scalp disorders, such as warts, acne, dandruff, and psoriasis.... keratolytic drugs
There are various types.
Bulk-forming laxatives increase the volume and softness of faeces and make them easier to pass.
Stimulant laxatives stimulate the intestinal wall to contract and speed up the elimination of faeces.
Lubricant laxatives soften and facilitate the passage of faeces.
Osmotic laxatives increase the water content and volume of the faeces.
If used in excess, laxative drugs may cause diarrhoea, abdominal cramps, and flatulence, and may impair normal bowel function.... laxative drugs
These drugs help to prevent, or slow the progression of, severe atherosclerosis and coronary artery disease.
The most commonly used types are statins and fibrates.... lipid-lowering drugs
Common macrolides include azithromycin and erythromycin.... macrolide drugs
The drugs may cause muscle weakness and drowsiness. In rare cases, dantrolene causes liver damage.... muscle-relaxant drugs
Possible side effects of nitrate drugs include headache, flushing, and dizziness. Tolerance (the need for greater amounts of a drug for it to have the same effect) may develop when the drug is taken regularly.... nitrate drugs
Nonsteroidal anti-inflammatory drugs are widely used to relieve symptoms caused by types of arthritis, such as rheumatoid arthritis, osteoarthritis, and gout. They do not cure or halt the progress of disease. NSAIDs are also used in the treatment of back pain, menstrual pain, headaches, pain after minor surgery, and soft tissue injuries.
The drugs reduce pain and inflammation by blocking the production of prostaglandins (chemicals that cause inflammation and trigger transmission of pain signals to the brain).
NSAIDs may cause a wide range of side effects, the most important of which are nausea, indigestion, bleeding from the stomach, and, sometimes, peptic ulcer.... nonsteroidal anti-inflammatory drugs
Natural penicillins are derived from the mould PENICILLIUM; others are synthetic preparations.
Penicillins are used to treat many infective conditions, including tonsillitis, bronchitis, bacterial endocarditis, syphilis, and pneumonia.
They are also given to prevent rheumatic fever from recurring.
Common adverse effects of penicillins are an allergic reaction causing a rash, and diarrhoea.... penicillin drugs
The group includes chlorpromazine, fluphenazine, and perphenazine.... phenothiazine drugs
Oestrogen drugs are often used together with progestogen drugs.
Oestrogens suppress the production of gonadotrophin hormones, which stimulate cell activity in the ovaries. High doses are used in postcoital contraception to prevent conception (see contraception, emergency). They are also used to treat, or sometimes prevent, menopausal symptoms and disorders. Oestrogens may be used to treat certain forms of infertility, female hypogonadism, abnormal menstrual bleeding, prostatic cancer (see prostate, cancer of), and certain types of breast cancer.
Oestrogens may cause breast tenderness and enlargement, bloating, weight gain, nausea, reduced sex drive, depression, migraine, and bleeding between periods. Side effects often subside after 2 or 3 months. The drugs can increase the risk of abnormal blood clotting and susceptibility to high blood pressure (see hypertension). Oestrogen drugs should not be taken in pregnancy as they may adversely affect the fetus.... oestrogen drugs
Problems may also be caused in a developing baby if a pregnant woman drinks alcohol, smokes (see tobaccosmoking), or takes drugs of abuse. The babies of women who use heroin during pregnancy tend to have a low birthweight and a higher death rate than normal during the first few weeks of life. Babies of women who abuse drugs intravenously are at high risk of HIV infection.... pregnancy, drugs in
Dinoprostone is used with oxytocin for induction of labour.
Gemeprost softens and helps to dilate the cervix prior to inducing an abortion.
Alprostadil is used to treat newborn infants awaiting surgery for some congenital heart diseases.... prostaglandin drugs
When absorbed into the skin, psoralens react with ultraviolet light to cause skin darkening or inflammation.
Psoralen drugs may be used in conjunction with ultraviolet light (a combination called PUVA) to treat psoriasis and vitiligo.
Overexposure to ultraviolet light during treatment, or to too high a dose of a psoralen drug, may cause redness and blistering of the skin.
Psoralens in perfumes may cause photosensitivity.... psoralen drugs
Quinolones are used in the treatment of a wide range of conditions, including urinary tract infections, acute diarrhoeal diseases (such as that caused by salmonella infections), and enteric fever. Their absorption is reduced by antacids containing magnesium and aluminium.
Quinolones should be used with caution in patients with epilepsy, during pregnancy and breast-feeding, and in children and adolescents. Side effects include nausea, vomiting, diarrhoea, headache, sleep disorders, dizziness, rash, and blood disorders.... quinolone drugs
Overdose causes hyperventilation, tinnitus, sweating, abnormal bleeding, biochemical disturbances, and, in severe cases, convulsions and coma.... salicylate drugs
They include benzodiazepines, antihistamines, antidepressants, and chloral hydrate.
Sleeping drugs may cause drowsiness and impaired concentration on waking.
Long-term use may induce tolerance and dependence.... sleeping drugs
Stimulants are of 2 types: central nervous system stimulants (for example, amfetamines), which increase alertness; and respiratory stimulants (see analeptic drugs), which encourage breathing.... stimulant drugs
If taken with milk, tetracyclines are not absorbed effectively into the intestines.
Possible side effects include nausea, vomiting, diarrhoea, worsening of kidney disorders, rash, and itching.
Tetracyclines may discolour developing teeth and are therefore not usually prescribed for children under age 12 or pregnant women.... tetracycline drugs
Stimulants such as amfetamines can prevent fatigue and increase confidence.
Three types of hormone drugs may be abused: anabolic steroids (see steroids, anabolic) to speed muscle recovery after exercise; erythropoietin to boost the haemoglobin content of the blood, which may increase stamina; and growth hormone to stimulate muscle growth.
Analgesic drugs may be used to mask the pain of an injury.
Betablockers are taken to reduce tremor in sports that require a steady hand.
Aside from the health risks associated with abuse of these drugs, their use is prohibited in many competitive sports.... sport, drugs and
Thrombolytic drugs act within blood vessels to dissolve clots.
Possible adverse effects include abnormal bleeding and an allergic reaction.... thrombolytic drugs
Vasodilator drugs include ACE inhibitors, alphablockers, calcium channel blockers, nitrate drugs, and sympatholytic drugs.
They are used to treat disorders in which abnormal narrowing of blood vessels reduces blood flow through tissues, impairing the supply of oxygen.
Such disorders include angina pectoris and peripheral vascular disease.
Vasodilators are also used to treat hypertension and heart failure.
All vasodilator drugs may cause flushing, headaches, dizziness, fainting, and swollen ankles.... vasodilator drugs
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