Drug Interactions between Phrenilin Forte (old formulation) and Pyrelle HB
This report displays the potential drug interactions for the following 2 drugs:
- Phrenilin Forte (old formulation) (acetaminophen/butalbital)
- Pyrelle HB (butabarbital/hyoscyamine/phenazopyridine)
Interactions between your drugs
acetaminophen butabarbital
Applies to: Phrenilin Forte (old formulation) (acetaminophen / butalbital) and Pyrelle HB (butabarbital / hyoscyamine / phenazopyridine)
MONITOR: Barbiturates may increase the hepatotoxic potential of acetaminophen and decrease its therapeutic effects. The mechanism may be related to accelerated CYP450 metabolism of acetaminophen with consequent increase in hepatotoxic metabolites. This interaction is of greatest concern in cases of acetaminophen overdose.
MANAGEMENT: Monitoring for altered efficacy and safety is recommended. Prolonged use or high doses of acetaminophen should be avoided by patients on barbiturate therapy.
References
- Pirotte JH (1984) "Apparent potentiation by phenobarbital of hepatotoxicity from small doses of acetaminophen." Ann Intern Med, 101, p. 403
- Douidar SM, Ahmed AE (1987) "A novel mechanism for the enhancement of acetaminophen hepatotoxicity by phenobarbital." J Pharmacol Exp Ther, 240, p. 578-83
- Wright N, Prescott LF (1973) "Potentiation by previous drug therapy of hepatotoxicity following paracetamol overdose." Scott Med J, 18, p. 56-8
- Bock KW, Wiltfang J, Blume R, Ullrich D, Bircher J (1987) "Paracetamol as a test drug to determine glucuronide formation in man: effects of inducers and of smoking." Eur J Clin Pharmacol, 31, p. 677-83
acetaminophen butalbital
Applies to: Phrenilin Forte (old formulation) (acetaminophen / butalbital) and Phrenilin Forte (old formulation) (acetaminophen / butalbital)
MONITOR: Barbiturates may increase the hepatotoxic potential of acetaminophen and decrease its therapeutic effects. The mechanism may be related to accelerated CYP450 metabolism of acetaminophen with consequent increase in hepatotoxic metabolites. This interaction is of greatest concern in cases of acetaminophen overdose.
MANAGEMENT: Monitoring for altered efficacy and safety is recommended. Prolonged use or high doses of acetaminophen should be avoided by patients on barbiturate therapy.
References
- Pirotte JH (1984) "Apparent potentiation by phenobarbital of hepatotoxicity from small doses of acetaminophen." Ann Intern Med, 101, p. 403
- Douidar SM, Ahmed AE (1987) "A novel mechanism for the enhancement of acetaminophen hepatotoxicity by phenobarbital." J Pharmacol Exp Ther, 240, p. 578-83
- Wright N, Prescott LF (1973) "Potentiation by previous drug therapy of hepatotoxicity following paracetamol overdose." Scott Med J, 18, p. 56-8
- Bock KW, Wiltfang J, Blume R, Ullrich D, Bircher J (1987) "Paracetamol as a test drug to determine glucuronide formation in man: effects of inducers and of smoking." Eur J Clin Pharmacol, 31, p. 677-83
butabarbital butalbital
Applies to: Pyrelle HB (butabarbital / hyoscyamine / phenazopyridine) and Phrenilin Forte (old formulation) (acetaminophen / butalbital)
MONITOR: Central nervous system- and/or respiratory-depressant effects may be additively or synergistically increased in patients taking multiple drugs that cause these effects, especially in elderly or debilitated patients. Sedation and impairment of attention, judgment, thinking, and psychomotor skills may increase.
MANAGEMENT: During concomitant use of these drugs, patients should be monitored for potentially excessive or prolonged CNS and respiratory depression. Cautious dosage titration may be required, particularly at treatment initiation. Ambulatory patients should be counseled to avoid hazardous activities requiring mental alertness and motor coordination until they know how these agents affect them, and to notify their physician if they experience excessive or prolonged CNS effects that interfere with their normal activities.
References
- Hamilton MJ, Bush M, Smith P, Peck AW (1982) "The effects of bupropion, a new antidepressant drug, and diazepam, and their interaction in man." Br J Clin Pharmacol, 14, p. 791-7
- Stambaugh JE, Lane C (1983) "Analgesic efficacy and pharmacokinetic evaluation of meperidine and hydroxyzine, alone and in combination." Cancer Invest, 1, p. 111-7
- Sotaniemi EA, Anttila M, Rautio A, et al. (1981) "Propranolol and sotalol metabolism after a drinking party." Clin Pharmacol Ther, 29, p. 705-10
- Grabowski BS, Cady WJ, Young WW, Emery JF (1980) "Effects of acute alcohol administration on propranolol absorption." Int J Clin Pharmacol Ther Toxicol, 18, p. 317-9
- Lemberger L, Rowe H, Bosomworth JC, Tenbarge JB, Bergstrom RF (1988) "The effect of fluoxetine on the pharmacokinetics and psychomotor responses of diazepam." Clin Pharmacol Ther, 43, p. 412-9
- MacLeod SM, Giles HG, Patzalek G, Thiessen JJ, Sellers EM (1977) "Diazepam actions and plasma concentrations following ethanol ingestion." Eur J Clin Pharmacol, 11, p. 345-9
- Divoll M, Greenblatt DJ, Lacasse Y, Shader RI (1981) "Benzodiazepine overdosage: plasma concentrations and clinical outcome." Psychopharmacology (Berl), 73, p. 381-3
- Naylor GJ, McHarg A (1977) "Profound hypothermia on combined lithium carbonate and diazepam treatment." Br Med J, 2, p. 22
- Stovner J, Endresen R (1965) "Intravenous anaesthesia with diazepam." Acta Anaesthesiol Scand, 24, p. 223-7
- Driessen JJ, Vree TB, Booij LH, van der Pol FM, Crul JF (1984) "Effect of some benzodiazepines on peripheral neuromuscular function in the rat in-vitro hemidiaphragm preparation." J Pharm Pharmacol, 36, p. 244-7
- Feldman SA, Crawley BE (1970) "Interaction of diazepam with the muscle-relaxant drugs." Br Med J, 1, p. 336-8
- Ochs HR, Greenblatt DJ, Verburg-Ochs B (1984) "Propranolol interactions with diazepam, lorazepam and alprazolam." Clin Pharmacol Ther, 36, p. 451-5
- Desager JP, Hulhoven R, Harvengt C, Hermann P, Guillet P, Thiercelin JF (1988) "Possible interactions between zolpidem, a new sleep inducer and chlorpromazine, a phenothiazine neuroleptic." Psychopharmacology (Berl), 96, p. 63-6
- Tverskoy M, Fleyshman G, Ezry J, Bradley EL, Jr Kissin I (1989) "Midazolam-morphine sedative interaction in patients." Anesth Analg, 68, p. 282-5
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- Greb WH, Buscher G, Dierdorf HD, Koster FE, Wolf D, Mellows G (1989) "The effect of liver enzyme inhibition by cimetidine and enzyme induction by phenobarbitone on the pharmacokinetics of paroxetine." Acta Psychiatr Scand, 80 Suppl, p. 95-8
- Markowitz JS, Wells BG, Carson WH (1995) "Interactions between antipsychotic and antihypertensive drugs." Ann Pharmacother, 29, p. 603-9
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acetaminophen hyoscyamine
Applies to: Phrenilin Forte (old formulation) (acetaminophen / butalbital) and Pyrelle HB (butabarbital / hyoscyamine / phenazopyridine)
Anticholinergic agents may delay and/or decrease the gastrointestinal absorption of acetaminophen by reducing gastric motility and delaying gastric emptying. However, the clinical relevance is probably minimal.
References
- Nimmo J, Heading RC, Tothill P, Prescott LF (1973) "Pharmacological modification of gastric emptying: effects of propantheline and metoclopramide on paracetamol absorption." Br Med J, 1, p. 587-9
- Clark JM, Seager SJ (1983) "Gastric emptying following premedication with glycopyrrolate or atropine." Br J Anaesth, 55, p. 1195-9
- "Product Information. Transderm-Scop (scopolamine)." Ciba Self-Medication Inc
Drug and food interactions
acetaminophen food
Applies to: Phrenilin Forte (old formulation) (acetaminophen / butalbital)
GENERALLY AVOID: Chronic, excessive consumption of alcohol may increase the risk of acetaminophen-induced hepatotoxicity, which has included rare cases of fatal hepatitis and frank hepatic failure requiring liver transplantation. The proposed mechanism is induction of hepatic microsomal enzymes during chronic alcohol use, which may result in accelerated metabolism of acetaminophen and increased production of potentially hepatotoxic metabolites.
MANAGEMENT: In general, chronic alcoholics should avoid regular or excessive use of acetaminophen. Alternative analgesic/antipyretic therapy may be appropriate in patients who consume three or more alcoholic drinks per day. However, if acetaminophen is used, these patients should be cautioned not to exceed the recommended dosage (maximum 4 g/day in adults and children 12 years of age or older).
References
- Kaysen GA, Pond SM, Roper MH, Menke DJ, Marrama MA (1985) "Combined hepatic and renal injury in alcoholics during therapeutic use of acetaminophen." Arch Intern Med, 145, p. 2019-23
- O'Dell JR, Zetterman RK, Burnett DA (1986) "Centrilobular hepatic fibrosis following acetaminophen-induced hepatic necrosis in an alcoholic." JAMA, 255, p. 2636-7
- Seeff LB, Cuccherini BA, Zimmerman HJ, Adler E, Benjamin SB (1986) "Acetaminophen hepatotoxicity in alcoholics." Ann Intern Med, 104, p. 399-404
- Thummel KE, Slattery JT, Nelson SD (1988) "Mechanism by which ethanol diminishes the hepatotoxicity of acetaminophen." J Pharmacol Exp Ther, 245, p. 129-36
- McClain CJ, Kromhout JP, Peterson FJ, Holtzman JL (1980) "Potentiation of acetaminophen hepatotoxicity by alcohol." JAMA, 244, p. 251-3
- Kartsonis A, Reddy KR, Schiff ER (1986) "Alcohol, acetaminophen, and hepatic necrosis." Ann Intern Med, 105, p. 138-9
- Prescott LF, Critchley JA (1983) "Drug interactions affecting analgesic toxicity." Am J Med, 75, p. 113-6
- (2002) "Product Information. Tylenol (acetaminophen)." McNeil Pharmaceutical
- Whitcomb DC, Block GD (1994) "Association of acetaminopphen hepatotoxicity with fasting and ethanol use." JAMA, 272, p. 1845-50
- Bonkovsky HL (1995) "Acetaminophen hepatotoxicity, fasting, and ethanol." JAMA, 274, p. 301
- Nelson EB, Temple AR (1995) "Acetaminophen hepatotoxicity, fasting, and ethanol." JAMA, 274, p. 301
- Zimmerman HJ, Maddrey WC (1995) "Acetaminophen (paracetamol) hepatotoxicity with regular intake of alcohol: analysis of instances of therapeutic misadventure." Hepatology, 22, p. 767-73
butabarbital food
Applies to: Pyrelle HB (butabarbital / hyoscyamine / phenazopyridine)
GENERALLY AVOID: Concurrent acute use of barbiturates and ethanol may result in additive CNS effects, including impaired coordination, sedation, and death. Tolerance of these agents may occur with chronic use. The mechanism is related to inhibition of microsomal enzymes acutely and induction of hepatic microsomal enzymes chronically.
MANAGEMENT: The combination of ethanol and barbiturates should be avoided.
References
- Gupta RC, Kofoed J (1966) "Toxological statistics for barbiturates, other sedatives, and tranquilizers in Ontario: a 10-year survey." Can Med Assoc J, 94, p. 863-5
- Misra PS, Lefevre A, Ishii H, Rubin E, Lieber CS (1971) "Increase of ethanol, meprobamate and pentobarbital metabolism after chronic ethanol administration in man and in rats." Am J Med, 51, p. 346-51
- Saario I, Linnoila M (1976) "Effect of subacute treatment with hypnotics, alone or in combination with alcohol, on psychomotor skills related to driving." Acta Pharmacol Toxicol (Copenh), 38, p. 382-92
- Stead AH, Moffat AC (1983) "Quantification of the interaction between barbiturates and alcohol and interpretation of fatal blood concentrations." Hum Toxicol, 2, p. 5-14
- Seixas FA (1979) "Drug/alcohol interactions: avert potential dangers." Geriatrics, 34, p. 89-102
butalbital food
Applies to: Phrenilin Forte (old formulation) (acetaminophen / butalbital)
GENERALLY AVOID: Concurrent acute use of barbiturates and ethanol may result in additive CNS effects, including impaired coordination, sedation, and death. Tolerance of these agents may occur with chronic use. The mechanism is related to inhibition of microsomal enzymes acutely and induction of hepatic microsomal enzymes chronically.
MANAGEMENT: The combination of ethanol and barbiturates should be avoided.
References
- Gupta RC, Kofoed J (1966) "Toxological statistics for barbiturates, other sedatives, and tranquilizers in Ontario: a 10-year survey." Can Med Assoc J, 94, p. 863-5
- Misra PS, Lefevre A, Ishii H, Rubin E, Lieber CS (1971) "Increase of ethanol, meprobamate and pentobarbital metabolism after chronic ethanol administration in man and in rats." Am J Med, 51, p. 346-51
- Saario I, Linnoila M (1976) "Effect of subacute treatment with hypnotics, alone or in combination with alcohol, on psychomotor skills related to driving." Acta Pharmacol Toxicol (Copenh), 38, p. 382-92
- Stead AH, Moffat AC (1983) "Quantification of the interaction between barbiturates and alcohol and interpretation of fatal blood concentrations." Hum Toxicol, 2, p. 5-14
- Seixas FA (1979) "Drug/alcohol interactions: avert potential dangers." Geriatrics, 34, p. 89-102
hyoscyamine food
Applies to: Pyrelle HB (butabarbital / hyoscyamine / phenazopyridine)
GENERALLY AVOID: Use of anticholinergic agents with alcohol may result in sufficient impairment of attention so as to render driving and operating machinery more hazardous. In addition, the potential for abuse may be increased with the combination. The mechanism of interaction is not established but may involve additive depressant effects on the central nervous system. No effect of oral propantheline or atropine on blood alcohol levels was observed in healthy volunteers when administered before ingestion of a standard ethanol load. However, one study found impairment of attention in subjects given atropine 0.5 mg or glycopyrrolate 1 mg in combination with alcohol.
MANAGEMENT: Alcohol should generally be avoided during therapy with anticholinergic agents. Patients should be counseled to avoid activities requiring mental alertness until they know how these agents affect them.
References
- Linnoila M (1973) "Drug effects on psychomotor skills related to driving: interaction of atropine, glycopyrrhonium and alcohol." Eur J Clin Pharmacol, 6, p. 107-12
Therapeutic duplication warnings
Therapeutic duplication is the use of more than one medicine from the same drug category or therapeutic class to treat the same condition. This can be intentional in cases where drugs with similar actions are used together for demonstrated therapeutic benefit. It can also be unintentional in cases where a patient has been treated by more than one doctor, or had prescriptions filled at more than one pharmacy, and can have potentially adverse consequences.
Tranquilizers
Therapeutic duplication
The recommended maximum number of medicines in the 'tranquilizers' category to be taken concurrently is usually one. Your list includes two medicines belonging to the 'tranquilizers' category:
- Phrenilin Forte (old formulation) (acetaminophen/butalbital)
- Pyrelle HB (butabarbital/hyoscyamine/phenazopyridine)
Note: In certain circumstances, the benefits of taking this combination of drugs may outweigh any risks. Always consult your healthcare provider before making changes to your medications or dosage.
Barbiturates
Therapeutic duplication
The recommended maximum number of medicines in the 'barbiturates' category to be taken concurrently is usually one. Your list includes two medicines belonging to the 'barbiturates' category:
- Phrenilin Forte (old formulation) (acetaminophen/butalbital)
- Pyrelle HB (butabarbital/hyoscyamine/phenazopyridine)
Note: In certain circumstances, the benefits of taking this combination of drugs may outweigh any risks. Always consult your healthcare provider before making changes to your medications or dosage.
See also
Drug Interaction Classification
Highly clinically significant. Avoid combinations; the risk of the interaction outweighs the benefit. | |
Moderately clinically significant. Usually avoid combinations; use it only under special circumstances. | |
Minimally clinically significant. Minimize risk; assess risk and consider an alternative drug, take steps to circumvent the interaction risk and/or institute a monitoring plan. | |
No interaction information available. |
Further information
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