Cialis Drug Interactions
Cialis is known to cause interactions with several other drugs and medication. People taking Cialis should be aware of these medicines.
Significant Drug Interactions
Some of the medications that can cause significant drug interaction with Cialis include the following:
CYP3A4 Inhibitos – Cialis is processed in the body by a certain enzyme known as CYP3A4. Certain medications can reduce the action of this enzyme which can decrease the breakdown and elimination of Cialis from the body. High levels of Cialis in the blood can cause serious side effects. Talk with your healthcare provider before using Cialis with a CYP3A4 inhibitor. Usually, your dose of either drug will need to be adjusted to avoid any side effects. Some CYP3A4 inhibitors include:
- Erythromycin (E-mycin)
- Ketoconazole (Nizoral)
- Itraconazole (Sporanox)
- Indinavir (Crixivan)
- Ritonavir (Norvir)
- Isoniazid
- Nefazodone (Serzone)
- Nelfinavir (Viracept)
- Nicardipine (Cardene)
- Posaconazole (Noxafil)
Antihypertensive medications – Cialis may decrease blood pressure, therefore combining it with antihypertensive medications can cause abnormally low blood pressure. Inform your healthcare provider if you are taking antihypertensive medications.
Alpha-Blockers – These medications are often used to treat high blood pressure (hypertension) as well as benign prostatic hyperplasia (BPH). Combining these medications with Cialis can cause abnormally low blood pressure. Inform your healthcare provider if you are taking such medications.
- Alfuzosin (Uroxatral)
- Doxazosin (Cardura)
- Phenoxybenzamine (Dibenzyline)
- Phentolamine (Regitine)
- Prazosin (Minipress)
- Silodosin (Rapaflo)
- Tamsulosin (Flomax)
- Terazosin (Hytrin)
Nitrate-containing medications – Cialis should not be taken with any nitrate-containing medications. Even if you use nitrate medications infrequently, you should never take Cialis since you do not exactly know when you will need to take nitrate. Concomitant use of Cialis and nitrates can cause blood pressure to drop to life-threatening levels. It can also lead to dizziness, fainting spells, stroke, or heart attack.
- Nitroglycerin tablets, spray or patches
- Isosorbide dinitrate (Isordil)
- Isosorbide mononitrate (Imdur)
- Amyl nitrite “poppers”
Other Phosphodiesterase-5 Inhibitors (PDE5 Inhibitors) – Cialis should not be combined with other PDE5 inhibitors, even if there are used for other medical purposes.
- Sildenafil (Viagra)
- Vardenafil (Levitra)
Bronchodilator – Concomitant use of theophylline and Cialis can cause a slight increase in heart rate. Tell your healthcare provider if you are taking this medication for necessary dose adjustments.
- Theophylline (Aerolate, Slo-bid, Theo-Dur)
If you are using any of the medications discussed, be sure to speak with your healthcare provider. Depending on your response to treatment, your healthcare provider may recommend switching or stopping one of the medications, or stopping both medications altogether.
Take note however that an interaction between two medications does not always require stopping any of the medication. Consult your healthcare provider for appropriate recommendations on how to manage the interactions.
This medication guide does not list all drugs that may interact with Cialis. Therefore, you should inform your healthcare provider of all the drugs (prescription and prescription) you take. Also, let your healthcare provider know if you are using caffeine, cigarette, alcohol and street drugs as these substances can also interact with this medication.
