Drug Interactions between Flomax and pramlintide

ADJUST DOSING INTERVAL: Food may delay the gastrointestinal absorption of tamsulosin. The time to maximum plasma concentration (Tmax) is reached by 4 to 5 hours under fasted conditions and by 6 to 7 hours when tamsulosin is administered with food. The delay in Tmax has the desirable effect of smoothing the tamsulosin plasma concentration profile, thereby reducing fluctuation of the plasma peak and trough concentrations with multiple dosing. Food may also affect the extent of absorption of tamsulosin. It has been reported that taking tamsulosin under fasted conditions results in a 30% increase in bioavailability (AUC) and 40% to 70% increase in peak plasma concentration (Cmax) compared to fed conditions. The effects of food on the pharmacokinetics of tamsulosin are consistent regardless of whether tamsulosin is taken with a light meal or a high-fat meal.

MANAGEMENT: To ensure uniformity of absorption, tamsulosin should be administered approximately one-half hour following the same meal each day.

ADJUST DOSING INTERVAL: Pramlintide slows gastric emptying and may delay the absorption of concomitantly administered oral medications. In a pharmacokinetic study of 24 patients with type 2 diabetes, coadministration with pramlintide (120 mcg) decreased the peak plasma concentration (Cmax) of acetaminophen (1000 mg) by 29% and increased its time to peak plasma concentration (Tmax) based on the time of acetaminophen administration relative to pramlintide injection. Pramlintide significantly increased acetaminophen Tmax (range 48 to 72 minutes) when acetaminophen was administered simultaneously with or up to 2 hours following pramlintide injection, but it had negligible effect when acetaminophen was administered 1 to 2 hours before pramlintide injection.

MANAGEMENT: When rapid onset of a concomitantly administered oral medication is critical to its effectiveness, the medication should be administered at least 1 hour before or 2 hours after pramlintide injection.