Keflex and Fatigue - from FDA reports

Fatigue is found among people who take Keflex, especially for people who are female, 60+ old , have been taking the drug for < 1 month, also take medication Zometa, and have Pain. This review analyzes which people have Fatigue with Keflex. It is created by eHealthMe based on reports of 8,658 people who have side effects when taking Keflex from FDA , and is updated regularly.

Personalized health information

On eHealthMe you can find out what patients like me (same gender, age) reported their drugs and conditions on FDA since 1977. Our original studies have been referenced on 400+ peer-reviewed medical publications, including: The Lancet, and Mayo Clinic Proceedings.

On Mar, 21, 2018

8,658 people reported to have side effects when taking Keflex.
Among them, 964 people (11.13%) have Fatigue

Number of reports submitted per year:

Could Keflex cause Fatigue?

Time on Keflex when people have Fatigue *:

  • < 1 month: 86.67 %
  • 1 - 6 months: 11.11 %
  • 6 - 12 months: 0.0 %
  • 1 - 2 years: 0.0 %
  • 2 - 5 years: 2.22 %
  • 5 - 10 years: 0.0 %
  • 10+ years: 0.0 %

Gender of people who have Fatigue when taking Keflex *:

  • female: 63.62 %
  • male: 36.38 %

Age of people who have Fatigue when taking Keflex *:

  • 0-1: 0.38 %
  • 2-9: 0.51 %
  • 10-19: 2.68 %
  • 20-29: 7.39 %
  • 30-39: 8.15 %
  • 40-49: 16.82 %
  • 50-59: 25.61 %
  • 60+: 38.47 %

Top conditions involved for these people *:

  • Pain: 94 people, 9.75%
  • Osteoporosis (bones weak and more likely to break): 55 people, 5.71%
  • Metastases To Bone (cancer spreads to bone): 55 people, 5.71%
  • Multiple Myeloma (cancer of the plasma cells): 50 people, 5.19%
  • Breast Cancer: 44 people, 4.56%

Top co-used drugs for these people *:

  • Zometa: 284 people, 29.46%
  • Lasix: 210 people, 21.78%
  • Ambien: 202 people, 20.95%
  • Aredia: 193 people, 20.02%
  • Vicodin: 186 people, 19.29%

Top other side effects for these people *:

  • Stress And Anxiety: 399 people, 41.39%
  • Pain: 393 people, 40.77%
  • Weakness: 346 people, 35.89%
  • Back Pain: 328 people, 34.02%
  • Nausea (feeling of having an urge to vomit): 303 people, 31.43%

* Approximation only. Some reports may have incomplete information.

How to use the study: print a copy of the study and bring it to your health teams to ensure drug risks and benefits are fully discussed and understood.

Subscribe to the study: get notified of updates to the study.

Want to find out more about the FDA reports used in the study? You can request them from FDA.

Do you take Keflex and have Fatigue?

Related studies


Keflex has active ingredients of cephalexin. It is often used in infection. (latest outcomes from Keflex 9,505 users)


Fatigue (feeling of tiredness) has been reported by people with multiple sclerosis, rheumatoid arthritis, hepatitis c, high blood pressure, depression (latest reports from 406,378 Fatigue patients).

Drugs that are associated with Fatigue
Fatigue (4,338 drugs)
Could your condition cause Fatigue
Fatigue (5,396 conditions)
Expand the study to include all drugs with the same ingredients
Fatigue and drugs with ingredients of cephalexin. (1,945 reports)
Expand the study to include reports from both FDA and eHealthMe
Fatigue and Keflex from FDA and eHealthMe reports (981 reports)
Keflex side effects
Browse all side effects of Keflex
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

Analysis tools (to study 684 million drug outcomes from FDA)

  • Check symptoms - identify the cause of a symptom: from a drug or from a condition?
  • Check drugs - find out common side effects or drug interactions of my drugs.
  • Compare drugs - compare the side effects and efficacy of multiple drugs side by side.

What would happen?

Predict new side effects and undetected conditions when you take Keflex and have Fatigue

You are not alone. Join our personalized support groups:

Can you answer these questions

More questions for: Keflex, Fatigue

You may be interested in these posts

More posts for: Keflex, Fatigue

Recent updates

General studies
Active Support Groups
Recent Predictions
Personalized studies

NOTE: The study is based on active ingredients and brand name. Other drugs that have the same active ingredients (e.g. generic drugs) are NOT considered.

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 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, and has not been supported by scientific studies or clinical trials unless otherwise stated. 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.

You may report adverse side effects to the FDA at or 1-800-FDA-1088 (1-800-332-1088).

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