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Drug Interactions between aminophylline / ephedrine / guaifenesin / phenobarbital and Robitet 500

This report displays the potential drug interactions for the following 2 drugs:

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Interactions between your drugs

Moderate

tetracycline aminophylline

Applies to: Robitet 500 (tetracycline) and aminophylline / ephedrine / guaifenesin / phenobarbital

MONITOR: Coadministration of a tetracycline may decrease theophylline plasma clearance and increase theophylline levels. The mechanism is unknown. Data are available for minocycline, tetracycline, and doxycycline, but are conflicting in some cases. This interaction appears to be more problematic if a tetracycline is administered for more than five days. Patients with chronic obstructive pulmonary disease, congestive heart failure, or cirrhosis may have slower theophylline clearance rates; therefore, they may be at greater risk of developing theophylline toxicity.

MANAGEMENT: If these drugs are given concurrently, close clinical and laboratory monitoring of response and tolerance is recommended. Patients should be advised to notify their physician if they experience any signs of theophylline toxicity including nausea, vomiting, diarrhea, headache, restlessness, insomnia, seizures, or irregular heartbeats. It may be necessary to reduce theophylline dosage.

References

  1. Gotz VP, Ryerson GG "Evaluation of tetracycline on theophylline disposition in patients with chronic obstructive airways disease." Drug Intell Clin Pharm 20 (1986): 694-6
  2. McCormack JP, Reid SE, Lawson LM "Theophylline toxicity induced by tetracycline." Clin Pharm 9 (1990): 546-9
  3. Upton RA "Pharmacokinetic interactions between theophylline and other medication (Part I)." Clin Pharmacokinet 20 (1991): 66-80

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Moderate

PHENobarbital aminophylline

Applies to: aminophylline / ephedrine / guaifenesin / phenobarbital and aminophylline / ephedrine / guaifenesin / phenobarbital

MONITOR: Barbiturates may decrease serum levels and therapeutic effects of the methylxanthines. The mechanism is barbiturate induction of CYP450 3A4 and 1A2 hepatic metabolism of methylxanthines.

MANAGEMENT: Close observation for clinical and laboratory evidence of decreased methylxanthine effect is indicated if these drugs must be used together. Patients should be advised to notify their physician if they experience a worsening of their respiratory symptoms.

References

  1. Upton RA "Pharmacokinetic interactions between theophylline and other medication (Part I)." Clin Pharmacokinet 20 (1991): 66-80
  2. Bukowskyj M, Nakatsu K, Munt PW "Theophylline reassessed." Ann Intern Med 101 (1984): 63-73
  3. Landay RA, Gonzalez MA, Taylor JC "Effect of phenobarbital on theophylline disposition." J Allergy Clin Immunol 62 (1978): 27-9
  4. Dahlqvist R, Steiner E, Koike Y, von Bahr C, Lind M, Billing B "Induction of theophylline metabolism by pentobarbital." Ther Drug Monit 11 (1989): 408-10
View all 4 references

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Minor

ePHEDrine aminophylline

Applies to: aminophylline / ephedrine / guaifenesin / phenobarbital and aminophylline / ephedrine / guaifenesin / phenobarbital

Ephedrine-methylxanthine combinations are used for the treatment of asthma but the efficacy of the combination has been questioned. This combination may lead to increased xanthine side effects. The mechanism is unknown, but may be related to synergistic pharmacologic effects. Patients using this combination should be closely monitored for side effects such as nausea, vomiting, tachycardia, nervousness, or insomnia. If side effects are noted, the dosage of the xanthine may need to be decreased.

References

  1. Weinberger M, Bronsky E, Bensch GW, Bock GN, Yecies JJ "Interaction of ephedrine and theophylline." Clin Pharmacol Ther 17 (1975): 585-92
  2. Sims JA, doPico GA, Reed CE "Bronchodilating effect of oral theophylline-ephedrine combination." J Allergy Clin Immunol 62 (1978): 15-21
  3. Tinkelman DG, Avner SE "Ephedrine therapy in asthmatic children. Clinical tolerance and absence of side effects." JAMA 237 (1977): 553-7
  4. Weinberger MM, Brousky EA "Evaluation of oral bronchodilator therapy in asthmatic children: bronchodilators in asthmatic children." J Pediatr 84 (1974): 421-7
  5. Badiei B, Faciane J, Sly M "Effect of throphylline, ephedrine and theri combination upon exercise-induced airway obstruction." Ann Allergy 35 (1975): 32-6
View all 5 references

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Drug and food interactions

Major

PHENobarbital food

Applies to: aminophylline / ephedrine / guaifenesin / phenobarbital

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

  1. Gupta RC, Kofoed J "Toxological statistics for barbiturates, other sedatives, and tranquilizers in Ontario: a 10-year survey." Can Med Assoc J 94 (1966): 863-5
  2. Misra PS, Lefevre A, Ishii H, Rubin E, Lieber CS "Increase of ethanol, meprobamate and pentobarbital metabolism after chronic ethanol administration in man and in rats." Am J Med 51 (1971): 346-51
  3. Saario I, Linnoila M "Effect of subacute treatment with hypnotics, alone or in combination with alcohol, on psychomotor skills related to driving." Acta Pharmacol Toxicol (Copenh) 38 (1976): 382-92
  4. Stead AH, Moffat AC "Quantification of the interaction between barbiturates and alcohol and interpretation of fatal blood concentrations." Hum Toxicol 2 (1983): 5-14
  5. Seixas FA "Drug/alcohol interactions: avert potential dangers." Geriatrics 34 (1979): 89-102
View all 5 references

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Moderate

tetracycline food

Applies to: Robitet 500 (tetracycline)

ADJUST DOSING INTERVAL: Administration with food, particularly dairy products, significantly reduces tetracycline absorption. The calcium content of these foods forms nonabsorbable chelates with tetracycline.

MANAGEMENT: Tetracycline should be administered one hour before or two hours after meals.

References

  1. "Product Information. Achromycin (tetracycline)." Lederle Laboratories PROD (2001):
  2. "Product Information. Declomycin (demeclocycline)." Lederle Laboratories PROD (2001):

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Moderate

tetracycline food

Applies to: Robitet 500 (tetracycline)

GENERALLY AVOID: The bioavailability of oral tetracyclines and iron salts may be significantly decreased during concurrent administration. Therapeutic failure may result. The proposed mechanism is chelation of tetracyclines by the iron cation, forming an insoluble complex that is poorly absorbed from the gastrointestinal tract. In ten healthy volunteers, simultaneous oral administration of ferrous sulfate 200 mg and single doses of various tetracyclines (200 mg to 500 mg) resulted in reductions in the serum levels of methacycline and doxycycline by 80% to 90%, oxytetracycline by 50% to 60%, and tetracycline by 40% to 50%. In another study, 300 mg of ferrous sulfate reduced the absorption of tetracycline by 81% and that of minocycline by 77%. Conversely, the absorption of iron has been shown to be decreased by up to 78% in healthy subjects and up to 65% in patients with iron depletion when ferrous sulfate 250 mg was administered with tetracycline 500 mg. Available data suggest that administration of iron 3 hours before or 2 hours after a tetracycline largely prevents the interaction with most tetracyclines except doxycycline. Due to extensive enterohepatic cycling, iron binding may occur with doxycycline even when it is given parenterally. It has also been shown that when iron is administered up to 11 hours after doxycycline, serum concentrations of doxycycline may still be reduced by 20% to 45%.

MANAGEMENT: Coadministration of a tetracycline with any iron-containing product should be avoided if possible. Otherwise, patients should be advised to stagger the times of administration by at least three to four hours, although separating the doses may not prevent the interaction with doxycycline.

References

  1. Neuvonen PJ "Interactions with the absorption of tetracyclines." Drugs 11 (1976): 45-54
  2. Gothoni G, Neuvonen PJ, Mattila M, Hackman R "Iron-tetracycline interaction: effect of time interval between the drugs." Acta Med Scand 191 (1972): 409-11
  3. Venho VM, Salonen RO, Mattila MJ "Modification of the pharmacokinetics of doxycycline in man by ferrous sulphate or charcoal." Eur J Clin Pharmacol 14 (1978): 277-80
  4. "Product Information. Minocin (minocycline)." Lederle Laboratories PROD (2002):
  5. Campbell NR, Hasinoff BB "Iron supplements: a common cause of drug interactions." Br J Clin Pharmacol 31 (1991): 251-5
  6. Bateman FJ "Effects of tetracyclines." Br Med J 4 (1970): 802
  7. Neuvonen PJ, Gothoni G, Hackman R, Bjorksten K "Interference of iron with the absorption of tetracyclines in man." Br Med J 4 (1970): 532-4
  8. Greenberger NJ "Absorption of tetracyclines: interference by iron." Ann Intern Med 74 (1971): 792-3
  9. Neuvonen PJ, Penttila O "Effect of oral ferrous sulphate on the half-life of doxycycline in man." Eur J Clin Pharmacol 7 (1974): 361-3
  10. "Product Information. Seysara (sarecycline)." Allergan Inc (2018):
  11. "Product Information. Nuzyra (omadacycline)." Paratek Pharmaceuticals, Inc. (2018):
View all 11 references

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Moderate

ePHEDrine food

Applies to: aminophylline / ephedrine / guaifenesin / phenobarbital

MONITOR: Coadministration of two or more sympathomimetic agents may increase the risk of adverse effects such as nervousness, irritability, and increased heart rate. Central nervous system (CNS) stimulants, particularly amphetamines, can potentiate the adrenergic response to vasopressors and other sympathomimetic agents. Additive increases in blood pressure and heart rate may occur due to enhanced peripheral sympathetic activity.

MANAGEMENT: Caution is advised if two or more sympathomimetic agents are coadministered. Pulse and blood pressure should be closely monitored.

References

  1. Rosenblatt JE, Lake CR, van Kammen DP, Ziegler MG, Bunney WE Jr "Interactions of amphetamine, pimozide, and lithium on plasma norepineophrine and dopamine-beta-hydroxylase in schizophrenic patients." Psychiatry Res 1 (1979): 45-52
  2. Cavanaugh JH, Griffith JD, Oates JA "Effect of amphetamine on the pressor response to tyramine: formation of p-hydroxynorephedrine from amphetamine in man." Clin Pharmacol Ther 11 (1970): 656
  3. "Product Information. Adderall (amphetamine-dextroamphetamine)." Shire Richwood Pharmaceutical Company Inc PROD (2001):
  4. "Product Information. Tenuate (diethylpropion)." Aventis Pharmaceuticals PROD (2001):
  5. "Product Information. Sanorex (mazindol)." Novartis Pharmaceuticals PROD (2001):
  6. "Product Information. Focalin (dexmethylphenidate)." Mikart Inc (2001):
  7. "Product Information. Strattera (atomoxetine)." Lilly, Eli and Company (2002):
View all 7 references

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Moderate

aminophylline food

Applies to: aminophylline / ephedrine / guaifenesin / phenobarbital

MONITOR: Coadministration of two or more sympathomimetic agents may increase the risk of adverse effects such as nervousness, irritability, and increased heart rate. Central nervous system (CNS) stimulants, particularly amphetamines, can potentiate the adrenergic response to vasopressors and other sympathomimetic agents. Additive increases in blood pressure and heart rate may occur due to enhanced peripheral sympathetic activity.

MANAGEMENT: Caution is advised if two or more sympathomimetic agents are coadministered. Pulse and blood pressure should be closely monitored.

References

  1. Rosenblatt JE, Lake CR, van Kammen DP, Ziegler MG, Bunney WE Jr "Interactions of amphetamine, pimozide, and lithium on plasma norepineophrine and dopamine-beta-hydroxylase in schizophrenic patients." Psychiatry Res 1 (1979): 45-52
  2. Cavanaugh JH, Griffith JD, Oates JA "Effect of amphetamine on the pressor response to tyramine: formation of p-hydroxynorephedrine from amphetamine in man." Clin Pharmacol Ther 11 (1970): 656
  3. "Product Information. Adderall (amphetamine-dextroamphetamine)." Shire Richwood Pharmaceutical Company Inc PROD (2001):
  4. "Product Information. Tenuate (diethylpropion)." Aventis Pharmaceuticals PROD (2001):
  5. "Product Information. Sanorex (mazindol)." Novartis Pharmaceuticals PROD (2001):
  6. "Product Information. Focalin (dexmethylphenidate)." Mikart Inc (2001):
  7. "Product Information. Strattera (atomoxetine)." Lilly, Eli and Company (2002):
View all 7 references

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Therapeutic duplication warnings

No warnings were found for your selected drugs.

Therapeutic duplication warnings are only returned when drugs within the same group exceed the recommended therapeutic duplication maximum.

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Drug Interaction Classification

These classifications are only a guideline. The relevance of a particular drug interaction to a specific individual is difficult to determine. Always consult your healthcare provider before starting or stopping any medication.
Major Highly clinically significant. Avoid combinations; the risk of the interaction outweighs the benefit.
Moderate Moderately clinically significant. Usually avoid combinations; use it only under special circumstances.
Minor 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.
Unknown No interaction information available.

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

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