Megestrol Other names: Megestrol acetate

Megestrol should be used with caution in patients with a history of thrombophlebitis and in patients with severe impaired liver function.

Megace is not recommended for women who are pregnant.

Several reports suggest an association between intrauterine exposure to progestational drugs in the first trimester of pregnancy and genital abnormalities in male and female foetuses. The risk of hypospadias, 5 to 8 per 1,000 male births in the general population, may be approximately doubled with the exposure to progestational drugs. There are insufficient data to quantify the risk to exposed female foetuses, however some of these drugs induce mild virilisation of the external genitalia of the female foetuses.

If a patient is exposed to megestrol during the first four months of pregnancy or if she becomes pregnant whilst taking megestrol, she should be apprised of the potential risks to the foetus.

Women of child bearing potential should be advised to avoid becoming pregnant.

Megace is not recommended for women who are breast feeding. Because of the potential for adverse effects, nursing should be discontinued during treatment with megestrol.

There are no known effects of megestrol acetate on the ability to drive or operate machinery.

The main side-effect experienced by patients while taking megestrol acetate, particularly at high doses, is weight gain, which is usually not associated with water retention, but which is secondary to an increased appetite and food intake. Weight gain is associated with an increase in fat and body cell mass.

Constipation and urinary frequency have also been reported in patients who received high doses of megestrol acetate in clinical trials.

A rarely encountered side effect of prolonged administration of megestrol acetate is urticaria, presumably an idiosyncratic reaction to the drug. The drug is devoid of the myelosuppressive activity characteristic of many cytotoxic drugs and it causes no significant changes in haematology, blood chemistry or urinalysis.

Pituitary adrenal axis abnormalities including glucose intolerance, new onset diabetes, exacerbation of pre-existing diabetes with decreased glucose tolerance and Cushing’s syndrome have been reported with the use of megestrol acetate. Clinically apparent adrenal insufficiency has been rarely reported in patients shortly after discontinuing megestrol acetate. The possibility of adrenal suppression should be considered in all patients taking or withdrawing from chronic megestrol acetate therapy. Replacement stress doses of glucocorticoids may be indicated.

The list is presented by system organ class, MedDRA preferred term, and frequency using the following frequency categories: very common (≥1/10), common (≥1/100, <1/10), uncommon (≥1/1000, <1/100), rare (≥1/10000, <1/1000), very rare (<1/10000), and not known (cannot be estimated from the available data).

Neoplasms benign, malignant, and unspecified (including cysts and polyps)

Common: Tumour flare#

Endocrine disorders

Very common: Adrenal insufficiency, cushingoid, Cushing’s syndrome

Metabolism and nutrition disorders

Very common: Diabetes mellitus, glucose tolerance impaired, hyperglycaemia, increased appetite

Psychiatric disorders

Common: Mood altered

Nervous system disorders

Common: Carpal tunnel syndrome, lethargy

Cardiac disorders

Common: Cardiac failure

Vascular disorders

Very common: Thrombophlebitis, pulmonary embolism*, hypertension, hot flush

Respiratory, thoracic and mediastinal disorders

Very common: Dyspnoea

Gastrointestinal disorders

Common: Nausea, vomiting, diarrhoea, flatulence

Very common: Constipation

Skin and subcutaneous tissue disorders

Common: Rash, alopecia

Renal and urinary disorders

Common: Pollakiuria

Reproductive system and breast disorders

Common: Menrorrhagia, erectile dysfunction

General disorders and administration site condition

Common: Asthenia, pain, oedema

Investigations

Very common: Weight increased

^† Source of frequencies: Megestrol Acetate Oral, Corporate Product Labeling Profile (CPLP) dated 12 November 1996.
^# with or without hypercalcemia
* Pulmonary embolism (in some cases fatal)