How much Viagra should I take?

I agree with you 100mg. is too much, try 25mg. first and if nothing happens within 30 minutes try with another quarter (25mg.).

Interactions between your selected drugs
Moderate
metoprolol sildenafil
Applies to: Metoprolol Tartrate (metoprolol), Viagra (sildenafil)

Sildenafil can add to the blood pressure-lowering effect of metoprolol. Contact your doctor if you experience signs and symptoms of low blood pressure such as dizziness, lightheadedness, fainting, flushing, headache, or a rapid pulse or heart rate. You may be more likely to experience these problems at the beginning of treatment, following a dose increase, or when treatment is restarted after an interruption. Avoid driving or operating hazardous machinery until you know how the medications affect you, and use caution when getting up from a sitting or lying position. It is important to tell your doctor about all other medications you use, including vitamins and herbs. Do not stop using any medications without first talking to your doctor.

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Other drugs and diseases that your selected drugs interact with
Metoprolol Tartrate (metoprolol) interacts with more than 400 other drugs and more than 10 diseases.
Viagra (sildenafil) interacts with more than 200 other drugs and 9 diseases.
Interactions between your selected drugs and food
Moderate
metoprolol food
Applies to: Metoprolol Tartrate (metoprolol)

Food can enhance the levels of metoprolol in your body. You should take metoprolol at the same time each day, preferably with or immediately following meals. This will make it easier for your body to absorb the medication. Avoid drinking alcohol, which could increase drowsiness and dizziness while you are taking metoprolol. Metoprolol is only part of a complete program of treatment that also includes diet, exercise, and weight control. Follow your diet, medication, and exercise routines very closely.

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