Bactrim Drug Interactions

by on April 16, 2012

Bactrim has been noted to have negative interactions with other medications, by decreasing their efficacy or causing other negative side effects.

There are approximately 350 different known drugs that interact with Bactrim.

Some of these medications include:

Blood Thinners

One category of drugs that can lead to severe drug interactions with Bactrim is blood thinners.

Medications such as Warfarin, Coumdrin, Anisindione, Dicumarol and Indandione used in conjunction with Bactrim can result in serious bleeding issues.

Patients taking both substances should contact their doctor immediately if they notice dizziness, pain, headache, unusual bleeding (including increased menstrual flow), nosebleeds or bleeding from cuts. Urine that is brown or red and stools that are red or black may also indicate a serious drug interaction that requires attention from a physician.

ACE (Angiotensin Converting Enzyme) Inhibitors

Drugs in this category including Benazepril, Quinapril, Accuretic, Quinaretic, Ramipril (Altace), Lisinopril ( Prinivil, Zestril ) and Vaseretic can have a major drug interaction when used in conjunction with Bactrim.

Using ACE inhibitors with Bactrim can result in high potassium levels in the blood which is known as hyperkalemia. This disorder includes symptoms of nausea, fatigue, muscle weakness, tingling sensations, slowed heartbeat and weak pulse. In fact, hyperkalemia can lead to the heart stopping altogether. Another antibiotic may be better tolerated than Bactrim if an ACE inhibitor is necessary.

Tricyclic Antidepressants

Tricyclic antidepressants include medications such as Protriptyline (Vivactil), Imipramine Hydrochloride (Tofranil), Clomipramine (Anafranil) and Doxepin (Sinequan or Silenor).

When these drugs are used with Bactrim, they may not be as effective. Antidepressants that are not working correctly can pose a serious risk to the patient including depressed mood, fatigue and even suicidal ideation. Patients taking any tricyclic antidepressants need to monitor their mood and report any significant changes to the prescribing doctor.

Seizure Medications

Some seizure medications, including Phenytoin, are known to interact with Bactrim.

When both medications are taken, the Bactrim can increase the level of seizure medication found in the patient’s blood stream. The prescribing doctor should monitor blood levels and adjust the dosage as needed. Elevated blood levels of seizure medications can increase the patient’s risk of suffering from their side effects such as confusion, slurred speech, dizziness, insomnia, nausea, vomiting and constipation.

Other Drugs Not Recommended

Bactrim has a number of medications that are not recommended it be combined with unless absolutely necessary. These medications include Methorexate, Leucovorin, Levoleucovorin and Dofetilide. Patients should always follow a doctor’s advice as they have the training necessary to judge whether a medication’s potential risk may outweigh its potential benefit.

Bactrim has a large number of drugs that it interacts with, making it especially important to make sure that a prescribing physician knows about all of a patient’s medications and conditions. Drug interactions can lead to medications becoming completely ineffective or cause serious side effects. It is also important to ensure that all medications are taken exactly as prescribed for optimal results.