This information is generalized and not intended as specific medical advice. Consult your healthcare professional before taking or discontinuing any drug or commencing any course of treatment.
Moderate. These medicines may cause some risk when taken together. Contact your healthcare professional (e.g. doctor or pharmacist) for more information.
How the interaction occurs:
When these two medicines are taken together, your body may not process theophyllines properly.
What might happen:
The blood level of your theophylline may decrease and cause breathing problems.
What you should do about this interaction:
If your doctor prescribes these two medicines together, you may need to check your theophylline level more often. If you experience problems with your breathing or other effects, contact your doctor. It may be necessary to adjust the dose of your medicine.Your healthcare professionals (e.g. doctor or pharmacist) may already be aware of this drug interaction and may be monitoring you for it. Do not start, stop, or change the dosage of any medicine before checking with them first.
1.Piafsky KM, Sitar DS, Ogilvie RI. Effect of phenobarbital on the disposition of intravenous theophylline. Clin Pharmacol Ther 1977 Sep; 22(3):336-9.
2.Landay RA, Gonzalez MA, Taylor JC. Effect of phenobarbital on theophylline disposition. J Allergy Clin Immunol 1978 Jul;62(1):27-9.
3.Paladino JA, Blumer NA, Maddox RR. Effect of secobarbital on theophylline clearance. Ther Drug Monit 1983;5(1):135-9.
4.Saccar CL, Danish M, Ragni MC, Rocci ML Jr, Greene J, Yaffe SJ, Mansmann HC Jr. The effect of phenobarbital on theophylline disposition in children with asthma. J Allergy Clin Immunol 1985 Jun;75(6):716-9.
5.Gibson GA, Blouin RA, Bauer LA, Rapp RP, Tibbs PA. Influence of high-dose pentobarbital on theophylline pharmacokinetics: a case report. Ther Drug Monit 1985;7(2):181-4.
6.Yazdani M, Kissling GE, Tran TH, Gottschalk SK, Schuth CR. Phenobarbital increases the theophylline requirement of premature infants being treated for apnea. Am J Dis Child 1987 Jan;141(1):97-9.
7.Wilschanski M, Kaplan M. Phenobarbital increases aminophylline requirement in premature infants. Am J Dis Child 1988 Feb;142(2):122-3.
8.Dahlqvist R, Steiner E, Koike Y, von Bahr C, Lind M, Billing B. Induction of theophylline metabolism by pentobarbital. Ther Drug Monit 1989; 11(4):408-10.
9.Kandrotas RJ, Cranfield TL, Gal P, Ransom JL, Weaver RL. Effect of phenobarbital administration on theophylline clearance in premature neonates. Ther Drug Monit 1990 Mar;12(2):139-43.
10.Nicholson JP, Basile SA, Cury JD. Massive theophylline dosing in a heavy smoker receiving both phenytoin and phenobarbital. Ann Pharmacother 1992 Mar;26(3):334-6.