Interactions

Active ingredient Acetazolamide interacts in the following cases:

Tricyclic antidepressants

Concomitant administration of acetazolamide with tricyclic antidepressants, may through different mechanisms, to enhance their action.

Corticosteroids

Concomitant administration of acetazolamide with corticosteroids or ACTH increases risk of hypoglycaemia.

Sympathomimetics

Concomitant administration of acetazolamide with sympathomimetics, may through different mechanisms, to enhance their action.

Lactation

Acetazolamide has been detected in low levels in the milk of lactating women who have taken Acetazolamide. Although it is unlikely that this will lead to any harmful effects in the infant, extreme caution should be exercised when Acetazolamide is administered to lactating women.

Amphetamines

Concomitant administration of acetazolamide with amphetamines cause deceleration of amphetamine excretion by the kidneys. The intake of acetazolamide shortly after phentermine resulted in a decrease of the phentermine excretion during one day and in one subject in a suppression below the detection limit 4 h post dosing.

Digitalis

Concomitant administration of acetazolamide with digitalis increases the risk of digitalis toxicity (due to hypokalemia).

Erythromycin

Concomitant administration of acetazolamide with erythromycin, increases the antimicrobial action of erythromycin, in infections of the urinary tract because of the alkalinization of the urine by acetazolamide.

Lithium

Concomitant administration of acetazolamide with lithium may increase the excretion of lithium by the kidneys.

Methadone

Concomitant administration of acetazolamide with methadone causes slowing of methadone excretion by the kidneys.

Methenamine

Concomitant administration of acetazolamide with methenamine causing neutralization of methenamine antiseptic action at urinary system.

Phenobarbital

Concomitant administration of acetazolamide with phenobarbital may cause severe osteomalacia.

Phenytoin

Concomitant administration of acetazolamide with diphenylhydantoin or phenytoin may cause severe osteomalacia.

Primidone

Concomitant administration of acetazolamide with primidone causes a decrease in the concentration of primidone in plasma (probably due to a reduction in the rate of primidone absorption from the gut) resulting in loss of seizure control. Effects of acetazolamide on primidone plasma levels were studied in three patients. Apparent interaction occurred in two patients. Primidone was not detected in the plasma when given orally with acetazolamide in one patient. In another, peak serum concentration was delayed, with corresponding delays in urinary excretion of primidone and metabolites. Plasma and urine concentrations of the two metabolites, phenylethylmalonamide and phenobarbital, were also studied.

Procainamide

Concomitant administration of acetazolamide with procainamide may, through different mechanisms, to enhance their action.

Quinidine

Concomitant administration of acetazolamide with quinidine causes inhibition of excretion of quinidine from the kidneys, which increases significantly the concentration of anti-arrhythmic drug in the blood (signs of poisoning).The acetazolamide inhibits the excretion of quinidine.

Quinine

Concomitant administration of acetazolamide with quinine causes slowing of quinine excretion by the kidneys. Antacids interfere with gastrointestinal drug absorption by either increasing or decreasing the rate at which a drug is absorbed, or the total quantity absorbed. Antacids influence drug absorption by alteration of ionization state or solubility, factors dependent upon pH. Antacids also delay gastric emptying and are capable of chelation and adsorption with susceptible products. Many of these factors participate to produce the effect on gastrointestinal drug absorption in individual patients.

Pulmonary obstruction or emphysema

In patients with pulmonary obstruction or emphysema where alveolar ventilation may be impaired, acetazolamide which may aggravate acidosis, should be used with caution.

Gallamine

Concomitant administration of acetazolamide with gallamine may through different mechanisms to enhance their action.

Pregnancy

Acetazolamide has been reported to be teratogenic and embryotoxic in rats, mice, hamsters and rabbits at oral or parenteral doses in excess of ten times those recommended in human beings. Although there is no evidence of these effects in human beings, there are no adequate and well-controlled studies in pregnant women. Therefore, acetazolamide should not be used in pregnancy, especially during the first trimester.

Nursing Mothers

Acetazolamide has been detected in low levels in the milk of lactating women who have taken acetazolamide. Although it is unlikely that this will lead to any harmful effects in the infant, extreme caution should be exercised when acetazolamide is administered to lactating women.

Effects on Ability to Drive and Use Machines

Increasing the dose does not increase the diuresis and may increase the incidence of drowsiness and/or paraesthesia. Less commonly, fatigue, dizziness and ataxia have been reported. Disorientation has been observed in a few patients with oedema due to hepatic cirrhosis. Such cases should be under close supervision. Transient myopia has been reported.

These conditions invariably subside upon diminution or discontinuance of the medication.