butalbital/acetaminophen (Phrenilin Forte, Phrenilin, Bupap, Orbivan CF)
Classes: Analgesics, Barbiturate Combos
Dosing and uses of Phrenilin Forte, Phrenilin (butalbital/acetaminophen)
Adult dosage forms and strengths
FDA is asking manufacturers to limit acetaminophen in prescription products to 325 mg/dosage unit; manufacturers have until January 14, 2014 to comply
butalbital/acetaminophen
tablet
- 50mg/300mg (Orbivan CF)
- 50mg/325mg (Phrenilin)
- 50mg/650mg (Bupap)
capsule
- 50mg/650mg (Phrenilin Forte)
Tension Headache
1-2 tab/cap PO q4hr; not to exceed 6 tab/cap per day
Not to exceed 4 g acetaminophen/24 hr
Renal Impairment
Mild-to-moderate: Administer lower dose
Severe: Use caution
Hepatic Impairment
Mild-to-moderate: Administer lower dose
Severe: Use caution
Pediatric dosage forms and strengths
FDA is asking manufacturers to limit acetaminophen in prescription products to 325 mg/dosage unit; manufacturers have until January 14, 2014 to comply
butalbital/acetaminophen
tablet
- 50mg/300mg (Orbivan CF)
- 50mg/325mg (Phrenilin)
- 50mg/650mg (Bupap)
capsule
- 50mg/650mg (Phrenilin Forte)
Tension Headache
<12 years: Safety and efficacy not established
≥12 years: As adults; 1-2 tab or cap PO q4hr; not to exceed 6 tab or cap per day
Not to exceed 4 g acetaminophen/24 hr
Geriatric dosage forms and strengths
Tension headache
1-2 tab/cap PO q4hr; not to exceed 6 tab/cap per day
Not to exceed 4 g acetaminophen/24 hr
Phrenilin Forte, Phrenilin (butalbital/acetaminophen) adverse (side) effects
Frequency not defined
ButalbitaL
- Dizziness, drowsiness, feeling of intoxication, lightheadedness, sedation
- Abdominal pain, nausea, vomiting
- Shortness of breath
Acetaminophen
- Angioedema, laryngeal edema
- Pruritic maculopapular rash urticaria
- Agranulocytosis, leukopenia, neutropenia, pancytopenia thrombocytopenia, thrombocytopenic purpura
- Hepatotoxicity
- Anaphylactoid reaction
Warnings
Black box warnings
Contains acetaminophen
Hepatotoxicity may occur with acetaminophen doses that exceed 4 grams/day (ie, 4,000 mg/day)
Acetaminophen associated with cases of acute liver failure, at times resulting in liver transplant and death
Most cases of liver injury are associated with the use of acetaminophen at doses that exceed 4 grams/day, and often involve more than 1 acetaminophen-containing product
New dosage limit allows no more than 325 mg/dosage unit for prescription medications that contain acetaminophen
Healthcare professionals can direct patients to take 1 or 2 tablets, capsules or other dosage units of a prescription product containing 325 mg of acetaminophen up to 6 times a day (12 dosage units) and still not exceed the maximum daily dose of acetaminophen (ie, 4000 mg/day)
Contraindications
Hypersensitivity
Hepatitis or severe hepatic/renal impairment
Repeated administration in patients w/ anemia, cardiovascular, pulmonary, or renal disease
Porphyria
Cautions
Acetaminophen associated with cases of acute liver failure, at times resulting in liver transplant and death; risk increases in individuals with underlying liver disease, alcohol ingestion, and/or use of more than 1 acetaminophen-containing product (see Black box warnings)
Acetaminophen: Risk for rare, but serious skin reactions that can be fatal; these reactions include Stevens-Johnson Syndrome (SJS), toxic epidermal necrolysis (TEN), and acute generalized exanthematous pustulosis (AGEP); symptoms may include skin redness, blisters and rash
G6PD deficiency
Avoid driving car or operating machinery
Pregnancy and lactation
Pregnancy category: C
Lactation: excreted in breast milk; caution advised
Pregnancy categories
A: Generally acceptable. Controlled studies in pregnant women show no evidence of fetal risk.
B: May be acceptable. Either animal studies show no risk but human studies not available or animal studies showed minor risks and human studies done and showed no risk.
C: Use with caution if benefits outweigh risks. Animal studies show risk and human studies not available or neither animal nor human studies done.
D: Use in LIFE-THREATENING emergencies when no safer drug available. Positive evidence of human fetal risk.
X: Do not use in pregnancy. Risks involved outweigh potential benefits. Safer alternatives exist.
NA: Information not available.
Pharmacology of Phrenilin Forte, Phrenilin (butalbital/acetaminophen)
Mechanism of action
Butalbital: Barbiturate; elicits generalized CNS depressant effects
Acts on hypothalamus to produce antipyresis; may work peripherally to pain impulse generation; may also inhibit prostaglandin synthesis in CNs
