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Qsymia and Viagra drug interactions - a phase IV clinical study of FDA data

Summary:

Drug interactions are reported among people who take Qsymia (phentermine hydrochloride; topiramate) and Viagra (sildenafil citrate). Common drug interactions include chronic kidney disease among males.

The phase IV clinical study analyzes what interactions people have when they take Qsymia and Viagra. It is created by eHealthMe based on reports of 15 people who take the same drugs from the FDA, and is updated regularly.

What is Qsymia?

Qsymia has active ingredients of phentermine hydrochloride; topiramate. It is often used in weight loss. eHealthMe is studying from 4,530 Qsymia users. Check the latest studies of Qsymia.

What is Viagra?

Viagra has active ingredients of sildenafil citrate. It is often used in erection problems. eHealthMe is studying from 63,865 Viagra users. Check the latest studies of Viagra.

On Jul, 11, 2026

15 people who take Qsymia and Viagra together, and have interactions are studied.

Qsymia and Viagra drug interactions.

What are the common drug interactions of Qsymia and Viagra, by gender? *:

female:

n/a

male:

  1. Chronic kidney disease
  2. Fanconi syndrome acquired (self developed genetic disease of kidney damage due to defective transport system)
  3. Dyspnoea (difficult or laboured respiration)
  4. Abdominal pain
  5. Blood iron decreased
  6. Bone density decreased
  7. Fall
  8. Muscle spasms (muscle contraction)
  9. Rib fracture
  10. Affective disorder (mental disorder)

What are the common drug interactions of Qsymia and Viagra, by age (0-1 to 60+)? *:

0-1:

n/a

2-9:

n/a

10-19:

n/a

20-29:

n/a

30-39:

n/a

40-49:

  1. Gait disturbance
  2. Pain
  3. Renal impairment (severely reduced kidney function)
  4. Bone density decreased
  5. Affective disorder (mental disorder)
  6. Depression
  7. Drug ineffective
  8. Feeling hot
  9. Head injury
  10. Lacrimation increased

50-59:

n/a

60+:

  1. Chronic kidney disease
  2. Glomerulonephritis acute (rapid group of conditions that affect parts of the kidneys called glomeruli)
  3. Renal failure (kidney dysfunction)

What are the existing conditions these people have? *

  1. Narcolepsy (brain's inability to regulate sleep-wake cycles normally): 10 people, 66.67%
  2. Hiv Infection: 3 people, 20.00%
  3. Muscle Contractions Involuntary (uncontrolled muscle contraction): 2 people, 13.33%
  4. High Blood Pressure: 2 people, 13.33%
  5. Head Injury: 2 people, 13.33%
  6. Depression: 2 people, 13.33%
  7. Back Pain: 2 people, 13.33%
  8. Weight Loss: 1 person, 6.67%
  9. Sleep Disorder: 1 person, 6.67%
  10. Infection: 1 person, 6.67%

* Approximation only. Some reports may have incomplete information.

Do you take Qsymia and Viagra?

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Related studies:

Effectiveness of, side effects of, and alternative drugs to the 2 drugs:

Browse all drug interactions of Qsymia and Viagra:

a b c d e f g h i j k l m n o p q r s t u v w x y z

Sub-studies by gender and age:

Female: 0-1 2-9 10-19 20-29 30-39 40-49 50-59 60+

Male: 0-1 2-9 10-19 20-29 30-39 40-49 50-59 60+

Browse all side effects of Qsymia:

a b c d e f g h i j k l m n o p q r s t u v w x y z

Browse all side effects of Viagra:

a b c d e f g h i j k l m n o p q r s t u v w x y z

Browse all interactions between Qsymia and drugs from A to Z:

a b c d e f g h i j k l m n o p q r s t u v w x y z

Browse all interactions between Viagra and drugs from A to Z:

a b c d e f g h i j k l m n o p q r s t u v w x y z

Related publications that referenced our studies

How the study uses the data?

The study uses data from the FDA. It is based on phentermine hydrochloride; topiramate and sildenafil citrate (the active ingredients of Qsymia and Viagra, respectively), and Qsymia and Viagra (the brand names). Other drugs that have the same active ingredients (e.g. generic drugs) are not considered. Dosage of drugs is not considered in the study.

How to use the study?

DO NOT STOP MEDICATIONS without first consulting your doctor. If there are any serious or long term adverse effects discovered in the study, discuss the study with your doctor to ensure that proper medication management will be in place if applicable.

Who is eHealthMe?

With medical big data and proven AI/ML algorithms, eHealthMe provides a platform for everyone to run phase IV clinical trials. We study millions of patients and 5,000 more each day. Results of our real-world drug study have been referenced on 800+ peer-reviewed medical publications, including The Lancet, Mayo Clinic Proceedings, and Nature. Our analysis results are available to researchers, health care professionals, patients (testimonials), and software developers (open API).

WARNING, DISCLAIMER, USE FOR PUBLICATION

WARNING: Please DO NOT STOP MEDICATIONS without first consulting a physician since doing so could be hazardous to your health.

DISCLAIMER: All material available on eHealthMe.com is for informational purposes only, and is not a substitute for medical advice, diagnosis, or treatment provided by a qualified healthcare provider. All information is observation-only. Our phase IV clinical studies alone cannot establish cause-effect relationship. Different individuals may respond to medication in different ways. Every effort has been made to ensure that all information is accurate, up-to-date, and complete, but no guarantee is made to that effect. The use of the eHealthMe site and its content is at your own risk.

If you use this eHealthMe study on publication, please acknowledge it with a citation: study title, URL, accessed date.

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