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Humulin R

Humulin R Side Effects

Robert Chad Hakim, PharmD, BCCCPConnie Zheng, PharmD
Reviewed by Robert Chad Hakim, PharmD, BCCCP, Connie Zheng, PharmD
Last reviewed on October 2, 2024

The following side effects may get better over time as your body gets used to the medication. Let your healthcare provider know immediately if you continue to experience these symptoms or if they worsen over time.

Common Side Effects

  • Low blood sugar
  • Reactions where the medication is injected (e.g., redness, swelling, itching)

Less Common Side Effects

Humulin R serious side effects

Contact your healthcare provider immediately if you experience any of the following.

  • Severely low blood sugar: dizziness, shakiness, feeling confused, feeling irritable or anxious, feeling faint, sweating, extreme hunger, can't think clearly
  • Dangerously low potassium levels: weakness, muscle cramps or twitches, constipation, abnormal heartbeat, tiredness, trouble breathing
  • Severe allergic reaction: rash; hives; swelling of face, tongue, and throat; trouble breathing

Source: DailyMed

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The following Humulin R side effects have also been reported

Along with its needed effects, a medicine may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor immediately if any of the following side effects occur:

Incidence not known

Anxiety

blurred vision

chills

cold sweats

confusion

convulsions

cool, pale skin

cough

decreased urine

depression

difficulty with swallowing

dizziness

dry mouth

fast heartbeat

flushing or redness of the skin

headache

hives, itching, or rash

increased hunger

increased thirst

irregular heartbeat

loss of appetite

muscle pain or cramps

nausea

nightmares

numbness or tingling in the hands, feet, or lips

puffiness or swelling of the eyelids or around the eyes, face, lips, or tongue

seizures

shakiness

slurred speech

sweating

swelling

tightness in the chest

unusual tiredness or weakness

unusually warm skin

Some side effects may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects. Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:

Incidence not known

Bleeding, blistering, burning, coldness, discoloration of the skin, feeling of pressure, hives, infection, inflammation, itching, lumps, numbness, pain, rash, redness, scarring, soreness, stinging, swelling, tenderness, tingling, ulceration, or warmth at the injection site

redistribution or accumulation of body fat

Other side effects not listed may also occur in some patients. If you notice any other effects, check with your healthcare professional.

Call your doctor for medical advice about side effects. You may report side effects to the FDA at 1-800-FDA-1088.

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Why trust our experts?

Robert Chad Hakim, PharmD, BCCCP, started his full-time career as a clinical pharmacist at UCLA Health in the general medicine, general cardiology, and ICU units after completing residency in 2016. He also was the preceptor for the general medicine rotation from 2017 to 2021, which was a required rotation for all pharmacy residents.
Connie Zheng, PharmD, is a drug information pharmacist at GoodRx and a licensed pharmacist in California. She has over 6 years of experience working in independent pharmacies.

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