Tadalafil is the active ingredient for Cialis drug which is used to treat erectile dysfunction. This drug is not suitable to be taken along with some other drugs, which could cause drug interactions leaving side effects to the users.Tadalafil Drug Interactions:There are total of 337 drugs that will interact with Tadalafil.>> 11 Major drugs interactions>> 174 Moderate drugs interactions>> 152 Minor drugs interactionsThe above mentioned are not only the drugs interactions, there are some other pills that are not suitable to take along with Generic Cialis. They are,# All other erectile dysfunction medications.# Antibiotics like telithromycin, clarithromycin, and erythromycin.# Major drug interaction nitrates such as amyl nitrate, isosorbide, riociguat, or telaprevir.# HIV/AIDS pills like indinavir, saquinavir, ritonavir, and atazanavir.Major Drug Interactions with Tadalafil Medications1. Amyl Nitrite: (Severe) Co administration of phosphodiesterase inhibitors with organic nitrates or nitrites in any dosage formulation is contraindicated. Consistent with their known effects on the nitric oxide/cGmp pathway, concomitant use of phosphodiesterase inhibitors and nitrates can cause severe hypo-tension, syncope, or myocardial infarction. Deaths have been reported in men who were using Sildenafil while taking nitrate or nitrite therapy for angina. 2. Riociguat: (Severe) Co administration of riociguat and Tadalafil is contraindicated due to the risk of hypo-tension. Do not administer riociguat 24 hours before or within 48 hours after Tadalafil. Consider initiating riociguat at a starting dose of 0.5 mg in patients at risk of hypo-tension. Monitor for signs and symptoms of hypo-tension during transition of therapy. 3. Telaprevir: (Severe) Tadalafil, when used for pulmonary arterial hypertension (PAH), is contraindicated with telaprevir. Co administration of telaprevir with phosphodiesterase type 5 (PDE5) inhibitors is expected to substantially increase their plasma concentrations and may result in increased associated adverse events including hypo-tension, syncope, visual changes, and prolonged erection. Telaprevir can be used cautiously with Tadalafil for erectile dysfunction; use Tadalafil at a reduced dose of 10 mg no more frequently than every 72 hours with increased monitoring for adverse reactions. What happens when drug interaction occurs with Tadalafil?1. When the generic Cialis is taken with some other drugs, it will lead to some serious conditions and would spoil your health.2. It is better to consult with the doctor before taking generic Cialis along with any other drugs, or it would cause you some side effects such as Change in vision, swelling in the hands, breathing problem and much more.3. There are also chances that one or more effects would cause severe health problems. The worst part is that, you would have taken Tadalafil in order to get effective erection but when the drug interactions happen it not only prevents you from getting an erection but it would also worsen your impotency condition.4. As the drug interactions would cause you adverse side effects, it is must that you have to be very careful while taking the treatment. Do follow you medications everyday without fail which is an essential and also check with the doctor frequently to know about the improvement in your health.5. In addition to that, it is also important that you have to check with the doctor about the pills that you are going to start taking during the Tadalafil treatment.6. This medication can be anything like over the counter pills, prescription drug, vitamin supplements, dietary pills and herbal drugs. Do not leave any single drug name while listing to your doctor.7. The medico would change the dosage strength or the time that you are supposed to take other medications to avoid the interaction.Tadalafil not only interacts with other drugs but it would also interact with alcohol, grapefruit or juice. Smoking during the treatment should also be avoided.