Opiate Health Dictionary

A condition in which a person infrequently passes hard FAECES (stools). Patients sometimes complain of straining, a feeling of incomplete evacuation of faeces, and abdominal or perianal discomfort. A healthy individual usually opens his or her bowels once daily but the frequency may vary, perhaps twice daily or once only every two or three days. Constipation is generally de?ned as fewer than three bowel openings a week. Healthy people may have occasional bouts of constipation, usually re?ecting a temporary change in diet or the result of taking drugs – for example, CODEINE – or any serious condition resulting in immobility, especially in elderly people.

Constipation is a chronic condition and must be distinguished from the potentially serious disorder, acute obstruction, which may have several causes (see under INTESTINE, DISEASES OF). There are several possible causes of constipation; those due to gastrointestinal disorders include:

Dietary: lack of ?bre; low ?uid consumption.

Structural: benign strictures (narrowing of gut); carcinoma of the COLON; DIVERTICULAR DISEASE.

Motility: poor bowel training when young; slow transit due to reduced muscle activity in the colon, occurring usually in women; IRRITABLE BOWEL SYNDROME (IBS); HIRSCHSPRUNG’S DISEASE.

•Defaecation: anorectal disease such as ?ssures, HAEMORRHOIDS and CROHN’S DISEASE; impaction of faeces. Non-gastrointestinal disorders causing constipation include:

Drugs: opiates (preparations of OPIUM), iron supplements, ANTACIDS containing aluminium, ANTICHOLINERGIC drugs.

Metabolic and endocrine: DIABETES MELLITUS, pregnancy (see PREGNANCY AND LABOUR), hypothyroidism (see under THYROID GLAND, DISEASES OF).

Neurological: cerebrovascular accidents (STROKE), MULTIPLE SCLEROSIS (MS), PARKINSONISM, lesions in the SPINAL CORD. Persistent constipation for which there is no

obvious cause merits thorough investigation, and people who experience a change in bowel habits – for example, alternating constipation and diarrhoea – should also seek expert advice.

Treatment Most people with constipation will respond to a dietary supplement of ?bre, coupled, when appropriate, with an increase in ?uid intake. If this fails to work, judicious use of LAXATIVES for, say, a month is justi?ed. Should constipation persist, investigations on the advice of a general practitioner will probably be needed; any further treatment will depend on the outcome of the investigations in which a specialist will usually be involved. Successful treatment of the cause should then return the patient’s bowel habits to normal.... constipation

A naturally occurring brain PEPTIDE, the effects of which resemble those of MORPHINE or other opiates (see ENDORPHINS; ENKEPHALINS).... encephalin

Peptides (see PEPTIDE) produced in the brain which have a pain-relieving action; hence their alternative name of opiate peptides. Their name is derived from endogenous MORPHINE. They have been de?ned as endogenous opiates or any naturally occurring substances in the brain with pharmacological actions resembling opiate alkaloids such as morphine. There is some evidence that the pain-relieving action of ACUPUNCTURE may be due to the release of these opiate peptides. It has also been suggested that they may have an antipsychotic action and therefore be of value in the treatment of major psychotic illnesses such as SCHIZOPHRENIA.... endorphins

An opioid analgesic drug derived from the opium poppy. Morphine is given to relieve severe pain caused by myocardial infarction, major surgery, serious injury, and cancer.Morphine blocks the transmission of pain signals at sites called opiate receptors in the brain and spinal cord. The drug also induces a sense of well-being or euphoria. Side effects include drowsiness, dizziness, constipation, nausea, vomiting, and confusion. Long-term use of morphine may lead to drug dependence, with severe flu-like symptoms when the drug is withdrawn (see withdrawal syndrome).... morphine

Bio-availability refers to the proportion of a drug reaching the systemic circulation after a particular route of administration. The most important factor is ?rst-pass metabolism – that is, pre-systemic metabolism in either the intestine or the liver. Many lipid-soluble drugs such as beta blockers (see BETAADRENOCEPTOR-BLOCKING DRUGS), some tricyclic ANTIDEPRESSANT DRUGS, and various opiate ANALGESICS are severely affected. Food may affect bio-availability by modifying gastric emptying, thus slowing drug absorption. Ingested calcium may combine with drugs such as tetracyclines, further reducing their absorption.... bio-availability

Physical or psychological reliance on a substance or an individual. A baby is naturally dependent on its parents, but as the child develops, this dependence lessens. Some adults, however, remain partly dependent, making abnormal demands for admiration, love and help from parents, relatives and others.

The dependence that most concerns modern society is one in which individuals become dependent on or addicted to certain substances such as alcohol, drugs, tobacco (nicotine), caffeine and solvents. This is often called substance abuse. Some people become addicted to certain foods or activities: examples of the latter include gambling, computer games and use of the Internet.

The 28th report of the World Health Organisation Expert Committee on Drug Dependence in 1993 de?ned drug dependence as: ‘A cluster of physiological, behavioural and cognitive phenomena of variable intensity, in which the use of a psychoactive drug (or drugs) takes on a high priority. The necessary descriptive characteristics are preoccupation with a desire to obtain and take the drug and persistent drug-seeking behaviour. Psychological dependence occurs when the substance abuser craves the drug’s desirable effects. Physical dependence occurs when the user has to continue taking the drug to avoid distressing withdrawal or abstinence symptoms. Thus, determinants and the problematic consequences of drug dependence may be biological, psychological or social and usually interact.’

Di?erent drugs cause di?erent rates of dependence: TOBACCO is the most common substance of addiction; HEROIN and COCAINE cause high rates of addiction; whereas ALCOHOL is much lower, and CANNABIS lower again. Smoking in the western world reached a peak after World War II with almost 80 per cent of the male population smoking. The reports on the link between smoking and cancer in the early 1960s resulted in a decline that has continued so that only around a quarter of the adult populations of the UK and USA smokes. Globally, tobacco consumption continues to grow, particularly in the developing world with multinational tobacco companies marketing their products aggressively.

Accurate ?gures for illegal drug-taking are hard to obtain, but probably approximately 4 per cent of the population is dependent on alcohol and 2 per cent on other drugs, both legal and illegal, at any one time in western countries.

How does dependence occur? More than 40 distinct theories or models of drug misuse have been put forward. One is that the individual consumes drugs to cope with personal problems or diffculties in relations with others. The other main model emphasises environmental in?uences such as drug availability, environmental pressures to consume drugs, and sociocultural in?uences such as peer pressure.

By contrast to these models of why people misuse drugs, models of compulsive drug use – where individuals have a compulsive addiction

– have been amenable to testing in the laboratory. Studies at cellular and nerve-receptor levels are attempting to identify mechanisms of tolerance and dependence for several substances. Classical behaviour theory is a key model for understanding drug dependence. This and current laboratory studies are being used to explain the reinforcing nature of dependent substances and are helping to provide an explanatory framework for dependence. Drug consumption is a learned form of behaviour. Numerous investigators have used conditioning theories to study why people misuse drugs. Laboratory studies are now locating the ‘reward pathways’ in the brain for opiates and stimulants where positive reinforcing mechanisms involve particular sectors of the brain. There is a consensus among experts in addiction that addictive behaviour is amenable to e?ective treatment, and that the extent to which an addict complies with treatment makes it possible to predict a positive outcome. But there is a long way to go before the mechanisms of drug addiction are properly understood or ways of treating it generally agreed.

Effects of drugs Cannabis, derived from the plant Cannabis sativa, is a widely used recreational drug. Its two main forms are marijuana, which comes from the dried leaves, and hashish which comes from the resin. Cannabis may be used in food and drink but is usually smoked in cigarettes to induce relaxation and a feeling of well-being. Heavy use can cause apathy and vagueness and may even cause psychosis. Whether or not cannabis leads people to using harder drugs is arguable, and a national debate is underway on whether its use should be legalised for medicinal use. Cannabis may alleviate the symptoms of some disorders – for example, MULTIPLE SCLEROSIS (MS) – and there are calls to allow the substance to be classi?ed as a prescribable drug.

About one in ten of Britain’s teenagers misuses volatile substances such as toluene at some time, but only about one in 40 does so regularly. These substances are given o? by certain glues, solvents, varnishes, and liquid fuels, all of which can be bought cheaply in shops, although their sale to children under 16 is illegal. They are often inhaled from plastic bags held over the nose and mouth. Central-nervous-system excitation, with euphoria and disinhibition, is followed by depression and lethargy. Unpleasant effects include facial rash, nausea and vomiting, tremor, dizziness, and clumsiness. Death from COMA and acute cardiac toxicity is a serious risk. Chronic heavy use can cause peripheral neuropathy and irreversible cerebellar damage. (See SOLVENT ABUSE (MISUSE).)

The hallucinogenic or psychedelic drugs include LYSERGIC ACID DIETHYLAMIDE (LSD) or acid, magic mushrooms, ecstasy (MDMA), and phencyclidine (PCP or ‘angel’ dust, mainly used in the USA). These drugs have no medicinal uses. Taken by mouth, they produce vivid ‘trips’, with heightened emotions and perceptions and sometimes with hallucinations. They are not physically addictive but can cause nightmarish bad trips during use and ?ashbacks (vivid reruns of trips) after use, and can probably trigger psychosis and even death, especially if drugs are mixed or taken with alcohol.

Stimulant drugs such as amphetamine and cocaine act like adrenaline and speed up the central nervous system, making the user feel con?dent, energetic, and powerful for several hours. They can also cause severe insomnia, anxiety, paranoia, psychosis, and even sudden death due to convulsions or tachycardia. Depression may occur on withdrawal of these drugs, and in some users this is su?ciently deterrent to cause psychological dependence. Amphetamine (‘speed’) is mainly synthesised illegally and may be eaten, sni?ed, or injected. Related drugs, such as dexamphetamine sulphate (Dexedrine), are prescribed pills that enter the black market. ECSTASY is another amphetamine derivative that has become a popular recreational drug; it may have fatal allergic effects. Cocaine and related drugs are used in medicine as local anaesthetics. Illegal supplies of cocaine (‘snow’ or ‘ice’) and its derivative, ‘crack’, come mainly from South America, where they are made from the plant Erythroxylon coca. Cocaine is usually sni?ed (‘snorted’) or rubbed into the gums; crack is burnt and inhaled.

Opiate drugs are derived from the opium poppy, Papaver somniferum. They are described as narcotic because they induce sleep. Their main medical use is as potent oral or injectable analgesics such as MORPHINE, DIAMORPHINE, PETHIDINE HYDROCHLORIDE, and CODEINE. The commonest illegal opiate is heroin, a powdered form of diamorphine that may be smoked, sni?ed, or injected to induce euphoria and drowsiness. Regular opiate misuse leads to tolerance (the need to take ever larger doses to achieve the same e?ect) and marked dependence. A less addictive oral opiate, METHADONE HYDROCHLORIDE, can be prescribed as a substitute that is easier to withdraw.

Some 75,000–150,000 Britons now misuse opiates and other drugs intravenously, and pose a huge public-health problem because injections with shared dirty needles can carry the blood-borne viruses that cause AIDS/HIV and HEPATITIS B. Many clinics now operate schemes to exchange old needles for clean ones, free of charge. Many addicts are often socially disruptive.

For help and advice see APPENDIX 2: ADDRESSES: SOURCES OF INFORMATION, ADVICE, SUPPORT AND SELF-HELP – National Dugs Helpline.

(See ALCOHOL and TOBACCO for detailed entries on those subjects.)... dependence

Also known as diacetyl morphine or diamorphine, this Class A controlled drug is an opiate

– a group which includes morphine, codeine, pethidine and methadone. It is a powerful analgesic and cough suppressant, but its capacity to produce euphoria rapidly induces DEPENDENCE. Popular with addicts, its mostly pleasant effects soon produce TOLERANCE; the need to inject the drug, with associated risks of HIV infection, has affected its use by addicts. Withdrawal symptoms include restlessness, insomnia, muscle cramps, vomiting and diarrhoea; signs include dilated pupils, raised pulse rate, and disturbed temperature control. Although rarely life-threatening, the effects of withdrawal may cause great distress, and for this reason methadone, which has a slower and less severe withdrawal syndrome, is commonly used when weaning addicts o? heroin. Legally still available to doctors in the UK, heroin is normally only used in patients with severe pain, or to comfort the dying.... heroin

An e?ective drug in the treatment of opioid poisoning. It blocks the effects of most opiates; given intravenously, it acts within 2–3 minutes. The drug is also given to newborn babies whose breathing has been depressed by narcotic drugs given to their mothers to relieve pain during childbirth.... naloxone

A drug that is an ANTAGONIST to narcotic substances (see NARCOTICS). Given orally, it is used in the maintenance treatment of HEROIN – and other opiate-dependent people.... naltrexone

A technique whereby a patient can deliver an analgesic substance (see ANALGESICS) in amounts related to the extent of the PAIN that he or she is suffering. For example, to combat post-operative pain, some hospitals use devices which allow patients to give themselves small intravenous amounts of opiates when they are needed. Pain is more e?ectively controlled if it is not allowed to reach a high level, a situation which tends to happen when patients receive analgesics only on ward drug rounds or when they ask the nursing sta? for them.... patient-controlled analgesia

Linn.

Family: Passifloraceae.

Habitat: Native of South-east America; grown in Indian gardens.

English: Wild Passion Flower, Maypop.

Action: Flowering and fruiting dried herb—mild sedative, hypnotic, tranquilizer, hypotensive, vasodilator, antispasmodic, anodyne, anti-inflammatory,

Key application: In nervous restlessness, irritability and difficulty in falling asleep. (German Commission E, ESCOP, The British Herbal Compendium, The British Herbal Pharmacopoeia, WHO.) The British Herbal Compendium also indicated it in neuralgia, dysmenorrhoea, and nervous tachycardia.

The herb contains flavonoids (up to 2.5%), in particular C-glycosylflavones; cyanogenic glycoside, gynocardine.

The alkaloid harman has been isolated, but the presence of harmine, har- maline, harmol and harmalol has been disputed. The alkaloid and flavonoids are reported to have sedative activity in animals. Apigenin exhibits antispasmodic and anti-inflammatory activity.

Passion Flower was formerly approved as an OTC sedative in the USA, but it was taken off the market in 1978 because safety and effectiveness had not been proven. An animal study in 1977 suggested that apigenin binds to central benzodi-zepine receptors (possibly causing anxiolytic effects). (Natural Medicines Comprehensive Database, 2007.)

The drug is used in homoeopathic medicine for epilepsy.

The herb exhibits a motility-inhi- biting effect in animal experiments.

Passion Flower, used as an adjunct to clonidine, was superior to clonidine for mental symptoms of opiate withdrawal. (Sharon M. Herr.)... passiflora incarnata

Papaver somniferum L. Prescription by a medical practitioner only. Contains morphine alkaloids and codeine. Analgesic, narcotic.

Although medication with opiates is addictive and its abuse ranges from dependence to death, use of crushed poppyheads as a topical poultice for crippling pain, as in terminal disease of chest or abdomen, is worthy of consideration. In an age before modern drugs and anaesthetics this was one of the few solaces available. Even today, there are a few situations for which this deep-acting pain-killer is indicated as, for instance, wounds healed but not without pain.

In spite of the plethora of modern drugs to combat the pain of terminal illness, few are as effective as the greatest anodyne of all time which led the eminent Sydenham to say “. . . if it were expunged from the pharmacopoeia, I would give up the practise of medicine”. ... opium poppy

One of a number of drugs subject to restricted use because of their potential for abuse. They include

opiates such as cocaine and morphine, amfetamine drugs, and barbiturate drugs. controlled trial A method of testing the effectiveness of new treatments or comparing different treatments. In a typical controlled drug trial, 2 comparable groups of patients suffering from the same illness are given courses of apparently identical treatment. However, only one group receives the new treatment; the second control group is given a placebo. Alternatively, the control group may be given an established drug that is already known to be effective. After a predetermined period, the 2 groups are assessed medically. Controlled trials must be conducted “blind’’ (the patients do not know which treatment they are receiving). In a “double-blind’’ trial, neither the patients nor the doctors who assess them know who is receiving which treatment. contusion Bruising to the skin and underlying tissues from an injury. convalescence The recovery period following an illness or surgery during which the patient regains strength before returning to normal activities.... controlled drug

n. an opioid *analgesic drug used mainly for pain relief during surgery (see opiate).... alfentanil

1. n. a drug that relieves pain. Nonopioid analgesics, such as *aspirin and *paracetamol, are used for the relief of headache, toothache, and mild rheumatic pain. More potent opioid analgesics, such as *morphine, *pethidine, *alfentanil, and *buprenorphine, are used to relieve moderate or severe pain; these drugs may produce *dependence and *tolerance (see opiate). Some analgesics, including aspirin and *indometacin, also reduce fever and inflammation and are used in rheumatic and other inflammatory conditions (see NSAID). 2. adj. relieving pain.... analgesic

n. a powerful opioid analgesic (see opiate) used for the relief of moderate to severe pain and to treat opioid dependence. Side-effects include drowsiness, nausea and vomiting, and constipation.... buprenorphine

n. the chemical name for heroin: a powerful opioid analgesic (see opiate) that is administered orally or by injection for the relief of acute and chronic pain, especially in terminal illness, and pulmonary oedema.... diamorphine

n. an opioid *analgesic used to relieve moderate to severe pain (see opiate). It sometimes causes nausea, dizziness, and constipation. Dependence of the *morphine type can also occur, but this is rare. Dihydrocodeine may be administered in combination with *paracetamol (as co-dydramol).... dihydrocodeine

(endomorphin) n. one of a group of chemical compounds, similar to the *encephalins, that occur naturally in the brain and have pain-relieving properties similar to those of the opiates. They are also responsible for sensations of pleasure. The endorphins are derived from a substance found in the pituitary gland known as beta-lipotrophin; they are thought to be concerned with controlling the activity of the endocrine glands.... endorphin

n. a potent opioid analgesic (see opiate) used for the relief of severe pain (for example in cancer patients already receiving other opioids) and for pain relief during surgery.... fentanyl

the principle that, where it is foreseen that a single action will have both a good and a bad outcome, a person may perform such an action provided that (a) he or she intends only the positive outcome, (b) the bad outcome is not disproportionate to the good, and (c) the good outcome is not a direct consequence of the bad. The classic example occurs where a terminally ill patient requires high doses of opiates for pain relief that may also depress respiratory function and hasten his or her death. In such a case the law holds that the doctor may supply the necessary dosage without this being considered tantamount to *euthanasia, even though the outcome will be the same, i.e. the morality of the action does not lie in its consequences (see consequentialism).... doctrine of double effect

(portosystemic encephalopathy) a condition in which brain function is impaired by the presence of toxic substances, absorbed from the colon, which are normally removed or detoxified by the liver. It occurs when the liver is severely damaged (as in cirrhosis) or bypassed. Symptoms include drowsiness, confusion, changes in personality, difficulty in performing tasks (e.g. writing), and coma. Treatment is mainly directed towards the underlying cause of liver disease and to any factors that may have precipitated the clinical deterioration (e.g. recent gastrointestinal haemorrhage, opiate medication, etc). Supportive measures consist of administering bowel cleansers (especially *lactulose, orally or by enema) and reducing protein and/or salt intake.... hepatic encephalopathy

n. a potent opioid (see opiate) administered to relieve severe pain and as a linctus to suppress coughs in terminal illness. An opioid agonist, it can also be substituted for heroin to prevent withdrawal symptoms in heroin dependence. Digestive upsets, drowsiness, and dizziness may occur, and prolonged use may lead to dependence.... methadone

n. a drug that induces stupor and insensibility and relieves pain. Now largely obsolete in medical contexts, the term was used particularly for morphine and other derivatives of opium (see opiate) but also referred to other drugs that depress brain function (e.g. general anaesthetics and hypnotics). In legal terms a narcotic is any addictive drug subject to illegal use.... narcotic

n. an extract from the poppy Papaver somniferum, which contains a number of alkaloids, principally morphine (which accounts for its analgesic, euphoric, and addictive effects: see opiate) with smaller amounts of codeine, papaverine, and others.... opium

n. an opioid analgesic (see opiate) used to treat moderate or severe pain, primarily in terminally ill patients. Common side-effects include drowsiness, dizziness, nausea, and constipation.... oxycodone

n. a potent opioid analgesic (see opiate) with mild sedative action, used to relieve moderate or severe pain of short duration (including that associated with childbirth). Side-effects may include nausea, dizziness, and dry mouth.... pethidine

n. an opioid analgesic (see opiate) used for the relief of moderate or severe pain. It causes less respiratory depression, constipation, and likelihood of dependence than other opioids.... tramadol