Effect of iron deficiency anaemia and its treatment on the absorption and elimination of phenformin.

1. The extent of phenformin absorption and its rate of urinary excretion have been assessed in adult patients with iron deficiency anaemia, a condition which compromises gastrointestinal function. 2. Phenformin (100 mg) was administered orally to patients before treatment, three days after the start of a course of iron treatment (oral 300 mg b.d. or total intravenous iron) and at the end of 28 days, when haemoglobin was over 10 gm%. 3. No significant difference was found between mean total amounts of phenformin and 4-hydroxyphenformin excreted in urine, before treatment or after 3 or 28 days replacement therapy. It is concluded that phenformin absorption is not affected by iron deficiency. 4. In addition, iron deficiency had no significant effect on phenformin elimination half-life.