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Drug Interactions between Combigan and D-G

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

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Interactions between your drugs

Major

dyphylline timolol ophthalmic

Applies to: D-G (dyphylline / guaifenesin) and Combigan (brimonidine / timolol ophthalmic)

GENERALLY AVOID: The pharmacologic effects of theophyllines and beta-blockers are opposite. Nonselective and high doses of cardioselective beta-blockers may cause severe or fatal bronchospasm by opposing theophylline-induced bronchodilation. Ophthalmic beta-blockers undergo significant systemic absorption and may also interact. In addition, propranolol and other beta-blockers may reduce the CYP450 hepatic metabolism of theophylline, and serum theophylline levels may be increased.

MANAGEMENT: Oral and ophthalmic nonselective beta-blockers (e.g., carteolol, carvedilol, levobunolol, metipranolol, nadolol, oxprenolol, penbutolol, pindolol, propranolol, sotalol, and timolol) are considered contraindicated in patients with bronchospastic diseases. Cardioselective beta-blockers should generally be avoided, or used with extreme caution if no other alternatives are available and the benefits outweigh the risks of potentially severe bronchospasm. If patients do receive this combination, they should be closely monitored for increased serum theophylline levels but decreased bronchodilatory effectiveness.

References

  1. Upton RA (1991) "Pharmacokinetic interactions between theophylline and other medication (Part II)." Clin Pharmacokinet, 20, p. 135-50
  2. Conrad KA, Nyman DW (1980) "Effects of metoprolol and propranolol on theophylline elimination." Clin Pharmacol Ther, 28, p. 463-7
  3. Horvath JS, Woolcock AJ, Tiller DJ, Donnelly P, Armstrong J, Caterson R (1978) "A comparison of metoprolol and propranolol on blood pressure and respiratory function in patients with hypertension." Aust N Z J Med, 8, p. 1-6
  4. Mue S, Sasaki T, Shibahara S, et al. (1979) "Influence of metoprolol on hemodynamics and respiratory function in asthmatic patients." Int J Clin Pharmacol Biopharm, 17, p. 346-50
  5. Lombardi TP, Bertino JS, Goldberg A, Middleton E, Slaughter RL (1987) "The effects of a beta-2 selective adrenergic agonist and a beta- nonselective antagonist on theophylline clearance." J Clin Pharmacol, 27, p. 523-9
View all 5 references

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Moderate

timolol ophthalmic brimonidine ophthalmic

Applies to: Combigan (brimonidine / timolol ophthalmic) and Combigan (brimonidine / timolol ophthalmic)

MONITOR: Topically administered alpha-2 adrenergic receptor agonists such as apraclonidine and brimonidine are systemically absorbed, with the potential for producing rare but clinically significant systemic effects such as hypotension and bradycardia. The possibility for an additive or potentiating effect on blood pressure and heart rate should be considered when used with other medications that affect these parameters, such as ophthalmic and systemic beta blockers, vasodilators, cardiac glycosides, and antihypertensive agents.

MANAGEMENT: Blood pressure and pulse rate should be monitored regularly when topical alpha-2 adrenergic receptor agonists are prescribed in combination with cardiovascular drugs. Patients should be advised to notify their physician if they experience slow pulse, irregular heartbeat, dizziness, lightheadedness, or syncope.

References

  1. King MH, Richards DW (1990) "Near syncope and chest tightness after administration of apraclonidine before argon laser iridotomy." Am J Ophthalmol, 110, p. 308-9
  2. "Product Information. Iopidine (apraclonidine ophthalmic)." Alcon Laboratories Inc
  3. Nordlund JR, Pasquale LR, Robin AL, Rudikoff MT, Ordman J, Chen KS, Walt J (1995) "The cardiovascular, pulmonary, and ocular hypotensive effects of 0.2% brimonidine." Arch Ophthalmol, 113, p. 77-83
  4. (2001) "Product Information. Alphagan (brimonidine ophthalmic)." Allergan Inc
  5. Walters TR (1996) "Development and use of brimonidine in treating acute and chronic elevations of intraocular pressure: a review of safety, efficacy, dose response, and dosing studies." Surv Ophthalmol, 41 ( Suppl, s19-26
  6. Pekdemir M, Yanturali S, Karakus G (2005) "More than just an ocular solution." Emerg Med J, 22, p. 753-4
  7. (2013) "Product Information. Mirvaso (brimonidine topical)." Galderma Laboratories Inc
View all 7 references

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Drug and food interactions

No alcohol/food interactions were found. However, this does not necessarily mean no interactions exist. Always consult your healthcare provider.

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.