Orange juice and an antacid (Mylanta) do not affect pharmacokinetics of cycloserine, but a high-fat meal delays its absorption.
Clinical evidence,mechanism, importance and management
A study in 12 healthy subjects found that bioavailability of a single 500mg dose of cycloserine was not affected by 15 mL of Mylanta (aluminium hydroxide 400 mg, magnesium hydroxide 400 mg, simeticone 40 mg per 5 mL). Mylanta was given 9 hrs before cycloserine, at same time as cycloserine, immediately after meals, and at bedtime on dosing day and following day (See reference number 1).
A study in 12 healthy subjects found that bioavailability of a single 500mg dose of cycloserine was not significantly affected by 240 mL of orange juice (See reference number 1). When cycloserine 500mg was given 15 minutes after start of a high-fat meal, which was completed within 30 minutes, AUC was not affected, but maximum serum levels were reduced by about 16 % and time to maximum levels was increased from 0.75 to
3.5 hours. It is possible that patients with relatively low plasma levels or patients receiving once rather than a twice daily dosage that delay in absorption could result in increased periods of subinhibitory levels (See reference number 1). However,there is no evidence to suggest that this is clinically significant.
1. Zhu M,Nix DE, Adam RD, Childs JM, Peloquin CA. Pharmacokinetics of cycloserine underfasting conditions and with high-fat meal, orange juice, and antacids. Pharmacotherapy (2001)21, 891–7.