Misoprostol Health Dictionary

Misoprostol: From 3 Different Sources


A synthetic prostaglandin drug that inhibits gastric secretion.

Misoprostol is used to prevent and treat peptic ulcers associated with use of nonsteroidal anti-inflammatory drugs.

Health Source: BMA Medical Dictionary
Author: The British Medical Association
A PROSTAGLANDIN analogue used to treat duodenal and gastric ulcers, and those induced by NON-STEROIDAL ANTI-INFLAMMATORY DRUGS (NSAIDS). It should not be taken by pregnant or breast-feeding women.
Health Source: Medical Dictionary
Author: Health Dictionary
n. a *prostaglandin drug administered in the prevention and treatment of peptic ulcer, especially when caused by nonsteroidal anti-inflammatory drugs (see NSAID), in which case it is given in conjunction with the NSAID (see diclofenac; naproxen). It is also used to terminate a pregnancy, being administered vaginally following *mifepristone. Possible side-effects include diarrhoea.
Health Source: Oxford | Concise Colour Medical Dictionary
Author: Jonathan Law, Elizabeth Martin

Abortion

Abortion is de?ned as the expulsion of a FETUS before it is normally viable, usually before 24 weeks of pregnancy. (There are exceptional cases nowadays in which fetuses as young as 22 weeks’ gestation have survived.) (See also PREGNANCY AND LABOUR.)

Spontaneous abortion Often called miscarriage, this may occur at any time before 28 weeks; 85 per cent occur in the ?rst 12 weeks of pregnancy. Of all diagnosed pregnancies, 25 per cent end in spontaneous abortion.

Spontaneous abortions occurring in early pregnancy are almost always associated with chromosomal abnormalities of the fetus. Other causes are uterine shape, maternal disorders such as DIABETES MELLITUS, diseases of the thyroid gland (see under ENDOCRINE GLANDS), and problems with the immune system (see IMMUNITY). Recurrent spontaneous abortion (that is, three or more) seems to be a particular problem in women who have an abnormal response of their immune system to pregnancy. Other factors include being older, having had a lot of babies previously, cigarette smoking and spontaneous (but not therapeutic) abortions in the past.

Early ULTRASOUND scans have altered the management of spontaneous abortions. These make it possible to distinguish between threatened abortion, where a woman has had some vaginal bleeding but the fetus is alive; inevitable abortion, where the neck of the uterus has started to open up; incomplete abortion, where part of the fetus or placenta is lost but some remains inside the uterus; and complete abortion. There is no evidence that bed rest is e?ective in stopping a threatened abortion becoming inevitable.

Inevitable or incomplete abortion will usually require a gynaecologist to empty (evacuate) the uterus. (Complete miscarriage requires no treatment.) Evacuation of the uterus is carried out using local or general anaesthetic, usually gentle dilatation of the neck of the uterus (cervix), and curetting-out the remaining products of the pregnancy.

A few late abortions are associated with the cervix opening too early, abnormal structural abnormalities of the uterus, and possibly infection in the mother.

Drugs are often used to suppress uterine contractions, but evidence-based studies show that these do not generally improve fetal salvage. In proven cases of cervical incompetence, the cervix can be closed with a suture which is removed at 37 weeks’ gestation. The evidence for the value of this procedure is uncertain.

Therapeutic abortion In the UK, before an abortion procedure is legally permitted, two doctors must agree and sign a form de?ned under the 1967 Abortion Act that the continuation of the pregnancy would involve risk – greater than if the pregnancy were terminated – of injury to the physical and/or mental health of the mother or any existing child(ren).

Legislation in 1990 modi?ed the Act, which had previously stated that, at the time of the abortion, the pregnancy should not have exceeded the 24th week. Now, an abortion may legally be performed if continuing the pregnancy would risk the woman’s life, or the mental health of the woman or her existing child(ren) is at risk, or if there is a substantial risk of serious handicap to the baby. In 95 per cent of therapeutic terminations in the UK the reason is ‘risk of injury to the physical or mental health of the woman’.

There is no time limit on therapeutic abortion where the termination is done to save the mother’s life, there is substantial risk of serious fetal handicap, or of grave permanent injury to the health of the mother.

About 190,000 terminations are carried out in the UK each year and only 1–1.5 per cent are over 20 weeks’ gestation, with the vast majority of these late abortions being for severe, late-diagnosed, fetal abnormality.

The maternal mortality from therapeutic abortion is less than 1 per 100,000 women and, provided that the procedure is performed skilfully by experienced doctors before 12 weeks of pregnancy, it is very safe. There is no evidence that therapeutic abortion is associated with any reduction in future fertility, increased rates of spontaneous abortion or preterm birth in subsequent pregnancies.

Methods of abortion All abortions must be carried out in premises licensed for doing so or in NHS hospitals. The method used is either surgical or medical, with the latter being used more and the former less as time goes on. Proper consent must be obtained, signed for and witnessed. Women under 16 years of age can consent to termination provided that the doctors obtaining the consent are sure she clearly understands the procedure and its implications. Parental consent in the under-16s is not legally required, but counselling doctors have a duty to record that they have advised young people to inform their parents. However, many youngsters do not do so. The woman’s partner has no legal say in the decision to terminate her pregnancy.

MEDICAL METHODS A combination of two drugs, mifepristone and a prostaglandin (or a prostaglandin-like drug, misoprostol – see PROSTAGLANDINS), may be used to terminate a pregnancy up to 63 days’ gestation. A similar regime can be used between nine and 12 weeks but at this gestation there is a 5 per cent risk of post-treatment HAEMORRHAGE.

An ultrasound scan is ?rst done to con?rm pregnancy and gestation. The sac containing the developing placenta and fetus must be in the uterus; the woman must be under 35 years of age if she is a moderate smoker, but can be over 35 if she is a non-smoker. Reasons for not using this method include women with diseases of the ADRENAL GLANDS, on long-term CORTICOSTEROIDS, and those who have a haemorrhagic disorder or who are on ANTICOAGULANTS. The drugs cannot be used in women with severe liver or kidney disease, and caution is required in those with CHRONIC OBSTRUCTIVE PULMONARY DISEASE (COPD), disease of the cardiovascular system, or prosthetic heart valves (see PROSTHESIS), as well as with those who have had a CAESAREAN SECTION or an ECTOPIC PREGNANCY in the past or who are being treated for HYPERTENSION.

Some clinics use this drug combination for pregnancies older than 12 weeks. In pregnancies approaching viability (20 weeks), pretreatment fetocide (killing of the fetus) with intrauterine drug therapy may be required.

SURGICAL METHODS Vacuum curettage is a method used up to 14–15 weeks. Some very experienced gynaecologists will perform abortions surgically by dilating the cervix and evacuating the uterine contents up to 22 weeks’ gestation. The greater the size of the pregnancy, the higher the risk of haemorrhage and perforation of the uterus. In the UK, illegal abortion is rare but in other countries this is not the case. Where illegal abortions are done, the risks of infection and perforation are high and death a de?nite risk. Legal abortions are generally safe. In the USA, partial-birth abortions are spoken of but, in fact, there is no such procedure recorded in the UK medical journals.... abortion

Diclofenac

n. an anti-inflammatory drug (see NSAID) used to relieve joint pain in osteoarthritis, rheumatoid arthritis, ankylosing spondylitis, acute gout, and actinic *keratosis, and also for pain relief after surgery. Possible side-effects include abdominal pain, nausea, and diarrhoea; gastric ulceration can be prevented by administering diclofenac in combination with *misoprostol.... diclofenac

Ulcer Healing Drugs

A variety of drugs with di?ering actions are available for the treatment of peptic ulcer, the composite title covering gastric ulcer (see STOMACH, DISEASES OF) and DUODENAL ULCER. Peptic ulceration may also involve the lower OESOPHAGUS, and after stomach surgery the junction of the stomach and small intestine.

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

Ulcer-healing Drugs

A group of drugs that are used to treat or prevent peptic ulcers. The eradication of HELICOBACTER PYLORI infection by treatment with antibiotic drugs and a drug to reduce acid secretion is now the preferred treatment for peptic ulceration.

Ulcer-healing drugs work in several ways. H-receptor antagonists function by blocking the effects of histamine, an action that reduces acid secretion in the stomach, thereby promoting the healing of ulcers. Taking antacid drugs regularly may be effective in healing duodenal ulcers because the drugs neutralize excess acid. Omeprazole and misoprostol work by reducing acid secretion. Other ulcer-healing drugs, such as sucralfate, are believed to form a protective barrier over the ulcer, allowing healing of the underlying tissues to take place.

The choice of ulcer-healing drug depends on the length of time symptoms have been present and the appearance of the ulcer during endoscopy.

In many cases of recent onset, a course of acidblocking drugs or antacids will give rapid relief.

Recurrent ulcers usually require treatment with antibiotic drugs.... ulcer-healing drugs

Mifepristone

n. a drug used to produce a medical abortion; it acts by blocking the action of *progesterone, which is essential for maintaining pregnancy. It is taken by mouth, followed after 36–48 hours by *gemeprost or *misoprostol intravaginally. Side-effects include faintness, headache, and vaginal bleeding.... mifepristone

Naproxen

n. an analgesic drug that also reduces inflammation and fever (see NSAID). It is used to treat rheumatoid arthritis, dysmenorrhoea, and gout. Side-effects may include digestive upsets and rashes: gastric bleeding can be prevented by administering naproxen in combination with *misoprostol.... naproxen

Prostaglandin

n. one of a group of hormone-like substances present in a wide variety of tissues and body fluids (including the uterus, brain, lungs, kidney, and semen). Prostaglandins have many actions; for example, they cause contraction of smooth muscle (including that of the uterus), dilation of blood vessels, and are mediators in the process of inflammation (aspirin and other *NSAIDs act by blocking their production). They are also involved in the production of mucus in the stomach, which provides protection against acid gastric juice; use of NSAIDs reduces this effect and predisposes to peptic ulceration, the principal side-effect of these drugs. There are nine classes of prostaglandins (PGA–I), within which individual prostaglandins are denoted by numerals (e.g. PGE1). Synthetic prostaglandins are used to induce labour or produce abortion (see dinoprostone; gemeprost) and to treat peptic ulcers (see misoprostol), congenital heart disease in newborn babies (see alprostadil), and glaucoma (see latanoprost).... prostaglandin



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