How Does Carisoprodol (Soma) Work? Know Its Side Effects, Precautions

Carisoprodol (Soma) also known as Soprodal and Vanadom. Soma is a compound of carisoprodol with codeine and aspirin (containing Aspirin, Carisoprodol, and Codeine).

Carisoprodol Side Effects & Precautions

Chemistry- Chemically, carisoprodol is N-isopropyl-2-methyl-2-propyl-1, 3-propanediol dicarbamate and the molecular formula is C12H24N2O4, with a molecular weight of 260.33. White crystalline powder. Soluble in alcohol, chloroform and acetone.

Taste of Carisoprodol (Soma)- Bitter.

How Does Carisoprodol (Soma) Work?

The mechanism of action is not clearly defined. Carisoprodol modulate neurotransmitters activities in spinal cord and reticular formation in brain. Research has not shown any changes in muscle actin myosin activities in muscles.

Prescription- Carisoprodol is available as white tablets.

Carisoprodol Dosage- Tablet strength is 250 mg or 350 mg, dosage is twice or three times a day. Dose depends on height, weight and tolerance.

Prescription Duration- Carisoprodol (Soma) is usually prescribed for 3 months duration, long-term benefit is not established. In some patients with cerebral palsy and severe daily spasm if other muscle relaxants are not beneficial and carisoprodol is effective then treatment is continued for prolonged period with careful observations for side effects.

Storage- Read pharmacy instruction on bottle. Stored on shelf at room temperature, strictly follow expiratory date.

Absorption- Carisoprodol is absorbed by intestinal mucosa and peak plasma concentration was observed after 1.5 to 2 hours. Bioavailability is not known.

Metabolism- Carisoprodol is metabolized by cytochrome enzyme CYP2C19 to form meprobamate in liver.

Elimination of Carisoprodol (Soma)

Carisoprodol is eliminated by both renal and non-renal routes like sweat and breast milk. Elimination half-life of approximately 2 hours. Elimination ½ life of metabolite meprobamate is approximately 9 to 10 hours. SOMA is excreted by kidney. Concentration of carisoprodol and meprobomate is high at toxic level in-patient with renal failure. Carisoprodol is dialyzed and eliminated by hemodialysis and peritoneal dialysis.

Hepatic Elimination: Patients with Reduced CYP2C19 Activity

SOMA (carisoprodol) should be used with caution in patients with liver disease and low CYP2C19 activity. The safety and pharmacokinetics of SOMA (carisoprodol) in patients with hepatic impairment have not been evaluated. Since SOMA (carisoprodol) is metabolized in the liver, caution should be exercised if SOMA (carisoprodol) is administered to patients with impaired hepatic function.

Indication For Use of Carisoprodol (Soma)

  • Chronic muscle spasmlower back, neck, upper and lower extremities
  • Strains,
  • Sprains and muscular pain after back surgery, joint replacement and instrumentation of fractured bones in extremities.
  • Other muscle injuries.
  • Acute, painful musculoskeletal conditions in adults.
  • Acute, idiopathic mechanical low back pain.

Side Effects of Carisoprodol (Soma)

Less Severe Side Effects of Carisoprodol (Soma):

  • General Examination- fever, weakness
  • Eyes- burning
  • CNS- Dizziness, drowsiness, clumsiness, headache, vertigo, ataxia, tremor, agitation, irritability, headache, depressive reactions, syncope, insomnia and seizures
  • Respiratory- trouble breathing.
  • Cardiovascular- fast heart rate, postural hypotension, and facial flushing
  • Gastrointestinal- upset stomach, vomiting.
  • Hematological- Leukopenia, pancytopenia

Severe Side Effects of Carisoprodol (Soma):

  • Eyes- vision loss.
  • CNS- Paralysis (loss of feeling), seizure, vertigo, agitation, confusion, syncope and feeling light headed, fainting.
  • General- Extreme weakness or lack of coordination.
  • Cardiovascular- Palpitation and fast heartbeat, continuous postural hypotension.

Carisoprodol (Soma) Precautions

Drug Interaction- Avoid use of Carisoprodol (Soma) if following drug or medications to be used simultaneously.

  • Alcohol
  • Opioids
  • Antihistaminic- Allergy medications, cough and cold syrups
  • Sedatives- Valium, Ativan
  • Antidepressants- Tricyclic antidepressants
  • Meprobamate, tybamate, or mebutamate;
  • Muscle Relaxants- Flexeril, Skelaxin Or Robaxin

Systemic Disease- Prescription of soma with following condition can be harmful. Extra precaution and strict supervision of treating physician is advised.

  • Blood disorder (acute intermittent porphyria)
  • Kidney disease
  • Liver disease
  • Seizure
  • Personal or family history of regular use/abuse of drugs/alcohol

Avoid- Carisoprodol is minor sedative and may cause drowsiness in normal dosage. Avoid taking carisoprodol in the following circumstances:

  • With alcoholic beverages.
  • Drive- If dizzy or drowsy. Do not drive.
  • Use of machinery.
  • Anesthesia.
  1. Pregnancy and Carisoprodol (Soma)- Avoid first 3 months. There are no scientific data on the use of SOMA (carisoprodol) during human pregnancy. Risk of carisoprodol or metabolites of carisoprodol meprobomate causing any congenital malformation is not documented, but for the sake of prevention it is advised to avoid carisoprodol for first trimester or first 3 months
  2. Carisoprodol (Soma) While Breast Feeding- Medication get excreted into breast milk. Infant may show symptoms of side effects. Consult neonatologist before breast-feeding. Soma Compound containing Aspirin and Carisoprodol may have long-term side effects, but scientific data is not available.

Drug Abuse And Dependence

  • Drug abuse cases have been documented. Abuse is common in patients with history of addiction.
  • Dependence – Prolonged use often causes abuse and dependence. Dependence is often because of side effect such as sedation.

Carisoprodol (Soma) Withdrawal and Abuse

  • Seen if discontinued abruptly

Pediatric Use of Carisoprodol (Soma)

The efficacy, safety, and pharmacokinetics of SOMA (carisoprodol) in pediatric patients less than 16 years of age are not known.

Geriatric Use of Carisoprodol (Soma)

The efficacy, safety, and pharmacokinetics of SOMA (carisoprodol) in patients over 65 years old is not known.

Carisoprodol (Soma) Medications Warning

In Case of Side Effects of Carisoprodol:

Report side effects to Food and Drug Administration’s (FDA) Contact information: or call 1-800-332-1088 (USA), 1-866-234-2345 (Canada).

  • Inform your doctor immediately
  • Go to nearest ER immediately if you cannot get hold of your doctor.
  • See list of side effects under description of each medications.
  • If side effects remain consistent until next dose or intolerable contact your physician or go to ER.
  • Signs of an allergic reaction: Hives; dyspnea; swelling of face, lips, tongue, and/or throat.

Carisoprodol (Soma) Prescription Instructions

  • Read direction carefully.
  • If you do not understand any part of instruction discuss with your doctor or pharmacist.
  • Follow the instructions carefully. Take the pills or liquid as prescribed. Do not increase or decrease frequency or quantity on your own judgment; you will be exposed to side effects or withdrawal symptoms.

In Case of Carisoprodol (Soma) Overdose:

  • Call 911, immediate resuscitation is most important initial step in treating life-threatening symptoms.
  • Call poison center 1-800 222 1222. Call after initial treatment is resume.

Sharing Medications

Do not share medications with your friend or relatives. Each individual has different history of allergies, drug interaction, drug shopping, addiction and other general health concern. Physician must prescribe medications after detail history and examination. Small error may be life threatening.

Pramod Kerkar, M.D., FFARCSI, DA
Pramod Kerkar, M.D., FFARCSI, DA
Written, Edited or Reviewed By: Pramod Kerkar, M.D., FFARCSI, DA Pain Assist Inc. This article does not provide medical advice. See disclaimer
Last Modified On:July 30, 2019

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