Linzess Drug Interactions

No drug-drug interaction studies have been performed. Linaclotide is rarely detectable in plasma following administration of the recommended clinical doses and in vitro studies have shown that linaclotide is neither a substrate nor an inhibitor/inducer of the cytochrome P450 enzyme system and does not interact with a series of common efflux and uptake transporters (see Pharmacology: Pharmacokinetics under Actions).
A food interaction clinical study in healthy subjects showed that linaclotide was not detectable in plasma either in fed or in fasted conditions at the therapeutic doses. Taking LINZESS in the fed condition produced more frequent and looser stools, as well as more gastrointestinal adverse events, than when taking it under fasting conditions (see Pharmacology: Pharmacodynamics under Actions). The capsule should be taken 30 minutes before a meal (see Dosage & Administration).
Concomitant treatment with proton pump inhibitors, laxatives or NSAIDs may increase the risk of diarrhoea. In cases of severe or prolonged diarrhoea, absorption of other oral medicinal products may be affected. The efficacy of oral contraceptives may be reduced and the use of an additional contraceptive method is recommended to prevent possible failure of oral contraception (see the prescribing information of the oral contraceptive). Caution should be exercised when prescribing medicinal products absorbed in the intestinal tract with a narrow therapeutic index such as levothyroxine as their efficacy may be reduced.