The potential side effects associated with the use of Cialis have been studied in nearly 5,000 healthy men worldwide. Reports have indicated that roughly 3% of users of Cialis had to stop taking the medication because of side effects.
In few cases, the following minor side effects or symptoms have been associated with taking Cialis:
- dyspepsia, which includes flatulence, stool disorders, rumbling and discomfort in the stomach, eructation, and/or nausea;
- pain in the back, hands, and feet;
- rhinitis, not associated with allergies or respiratory diseases;
- hot flashes and sweating;
- changes in color perception (noted in less than 0.1% of patients);
- increased fatigue;
- tachycardia and associated palpitations;
- fluctuations in blood pressure;
- hypotension with a change in body position;
- chest pain (angina);
- skin rashes and/or spontaneous erections not associated with sexual intercourse.
Possible symptoms associated with Cialis overdose have been attempted to be simulated in controlled laboratory conditions. However, it has been observed that even while ingesting 500 mg of tadalafil as a single dose or 100 mg several times a day in healthy men, the incidence of adverse events did not exceed the severity of side effects associated with consumption of standard dosages.
Common contraindications associated with prescribing Cialis for the treatment of erectile dysfunction are:
- high risk of an allergic reaction to tadalafil;
- lactose intolerance;
- heart attack or stroke risk;
- angina pectoris;
- chronic heart failure;
- loss of vision associated with ischemic impairment.
When other medications are consumed while taking tadalafil the following points should be considered:
- use of Cialis is contraindicated if already taking organic nitrates because of high risks associated with cardiovascular system complications;
- Cialis is not compatible with other medications taken for the treatment of erectile dysfunction;
- ketoconazole, itraconazole, and other medications associated with HIV therapy may increase the effects of Cialis;
- rifampicin, phenobarbital, and carbamazepine inhibit the activity of tadalafil;
- concurrent ingestion of antacids does not affect the potency of Cialis, but may reduce the rate of absorption;
- tadalafil modestly increases the effects of antihypertensive pharmacotherapies.
Even when used over long durations of time, the drug insert packet for Cialis indicates that this medication is not addictive.