Note: This document contains side effect information about acetaminophen / caffeine / phenyltoloxamine. Some dosage forms listed on this page may not apply to the brand name Flextra.

Applies to acetaminophen/caffeine/phenyltoloxamine: oral capsule.

Cardiovascular

Cardiovascular side effects have included palpitations, hypotension, and cardiac stimulation.^[Ref]

Gastrointestinal

Gastrointestinal side effects have included epigastric distress, diarrhea, intestinal cramps, nausea, xerostomia, and dryness of mouth, throat, and nose.^[Ref]

Dermatologic

Dermatologic side effects have included urticaria and rash. Acetaminophen has been associated with a risk of rare but potentially fatal serious skin reactions know as Stevens-Johnson syndrome (SJS), toxic epidermal necrolysis (TEN), and acute generalized exanthematous pustulosis (AGEP).^[Ref]

Hypersensitivity

Hypersensitivity side effects have included allergic reactions.^[Ref]

Hematologic

Hematologic side effects have included thrombocytopenia and agranulocytosis.^[Ref]

Musculoskeletal

Musculoskeletal side effects have included muscular weakness.^[Ref]

Genitourinary

Genitourinary side effects have included urinary retention.^[Ref]

Nervous system

Nervous system side effects have included dizziness, drowsiness, disturbed coordination, inability to concentrate, insomnia, tremors, nervousness, convulsions, irritability, and dependence.^[Ref]

Ocular

Ocular side effects have included blurred vision.^[Ref]

Renal

Renal side effects have included nephrotoxicity.^[Ref]

Metabolic

Metabolic side effects have included hyperglycemia.^[Ref]