Hello,

Thanks for your query.

Cialis is tadalafil is a PDE5 enzyme inhibitor so it causes dilatation of blood vessels.
Dilatation of blood vessels pushes more flow in the cavernous sinus in penis and helps in erection so this medicine helps in erectile.

The most common side effects when using tadalafil are headache, indigestion, back pain, muscle aches,dysfunction and hypotension so it should not be used with other antihypertensives and nitrates.

Losartan potassium is a medicine used as first line therapy for treating hypertension.It belongs to group of ACE inhibitors.The common side effects with losartan are headache;dizziness;fatigue;oedema;transient increase in liver function.

Again with losartan the dose need to be reduced when used with other antihypertensives.
So there is no study of direct drug interaction but since both of the medicines create hypotension it is better not to use both the medicines together unless your doctor has prescribed after physical examination.

Because after physical examination the Physician will titrate the dose of both the medicines so as to suit your body.

So take care.

Hope I have answered your query. Please accept my answer in case you do not have further queries.
Regards

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