A rare presentation of acute Intermittent Porphyria is described, in which withdrawal of an oral contraceptive (Gynovlar 21) provoked the first acute attack.
PIP: Estrogens, in common with barbiturates and other drugs provoking acute intermittent prophyria (AIP), increase the activity of delta-ALA synthetase. A case history documenting an AIP attack upon withdrawal of oral contraceptives (OCs) concluded that the patient's high endogenous estrogen secretion on withdrawal revealed an otherwise latent abnormality. A 29-year-old woman who had taken Gynovlar 21 for 8 years with no adverse effects complained of proximal myopathy 3 weeks after cessation of OCs. Though the initial complaint resolved spontaneously upon menstruation, 3 weeks later she complained of acute colicky abdominal pains, anorexia, and muscle aches. Gentamicin therapy was started, and emergency laparotomy was performed 2 days later after the patient developed ileus, sinus tachycardia (100/minute), and hypertension (150/110 mm of Hg). Laparotomy was essentially negative. Postoperatively, the sinus tachycardia and hypertension persisted; Tuinal administration resulted in return of muscle pains and clinical diagnosis of AIP. The patient was treated with Hycal, fluid restriction, and soluble aspirin. After 2 weeks she improved clinically and serum electrolytes were normal. Blood pressure settled to 130/80 and pulse rate to 90/minute. This case appears unique in that symptoms presented upon withdrawal of OCs.