Cyclobenzaprine vs. Valium (diazepam)

• Cyclobenzaprine and Valium (diazepam) are used to relieve muscle spasms.
• Cyclobenzaprine is used with rest and physical therapy for short-term relief of muscle spasms associated with acute painful muscle and skeletal conditions.
• Valium is mainly used to treat anxiety, for sedation during surgery, and for the treatment of agitation, tremors, delirium, seizures, and hallucinations resulting from alcohol withdrawal.
• Brand names for cyclobenzaprine include Flexeril, Amrix, and Fexmid.
• Cyclobenzaprine and Valium belong to different drug classes. Cyclobenzaprine is a muscle relaxant and Valium is a benzodiazepine.
• Side effects of cyclobenzaprine and Valium that are similar include drowsiness, fatigue, vision problems (blurred or double vision), and confusion.
• Side effects of cyclobenzaprine that are different from Valium include dry mouth, headaches, dizziness, nausea, constipation, unpleasant taste, nervousness, acid reflux, and abdominal pain or discomfort.
• Side effects of Valium that are different from cyclobenzaprine include diarrhea, rash, euphoria, loss of balance, excitability, muscle spasm, lack of sleep, rage, and speech problems.
• Withdrawal symptoms may occur if you suddenly stop taking Valium.

Cyclobenzaprine is a muscle relaxant used with rest and physical therapy for short-term relief of muscle spasms associated with acute painful muscle and skeletal conditions. It is only used short-tem, for up to two or three weeks. Cyclobenzaprine relieves muscle spasm due to local problems, that is, in the muscle itself and not in the nerves controlling the muscles. Cyclobenzaprine is believed to work through a complex mechanism within the nervous system, likely in the brainstem.

Valium (diazepam) is a benzodiazepine used to treat anxiety. Valium also is used for relief of muscle spasms in some neurological diseases, for sedation during surgery, and for the treatment of agitation, tremors, delirium, seizures, and hallucinations resulting from alcohol withdrawal. Other benzodiazepines also include alprazolam (Xanax), clonazepam (Klonopin), lorazepam (Ativan), and flurazepam (Dalmane). Valium and other benzodiazepines act by enhancing the effects of the neurotransmitter gamma-aminobutyric acid (GABA) in the brain. It is believed that excessive activity in the brain may lead to anxiety or other psychiatric disorders.

Cyclobenzaprine

The most common side effects of cyclobenzaprine include:

• Drowsiness
• Dry mouth
• Fatigue
• Headaches
• Dizziness

Other reported side effects include:

• Nausea
• Constipation
• Blurred vision,
• Unpleasant taste
• Nervousness
• Confusion
• Acid reflux
• Abdominal pain or discomfort

Possible serious side effects include:

• Seizures
• Abnormal heart beats
• Stroke
• Heart attacks
• Heat stroke

Abrupt cessation after prolonged therapy may cause withdrawal symptoms such as headaches, nausea, and weakness.

Valium

Warning: Diazepam can lead to addiction (dependency), especially when higher dosages are used over prolonged periods of time. In patients addicted to diazepam or after prolonged use, abrupt discontinuation may cause symptoms of withdrawal such as:

• Insomnia
• Headaches
• Nausea
• Vomiting
• Lightheadedness
• Sweating
• Anxiety
• Fatigue

Seizures can occur in more severe cases of withdrawal. Therefore, after extended use, diazepam should be slowly tapered under a doctor's supervision rather than abruptly stopped.

The most common side effects of diazepam are:

• Drowsiness
• Fatigue
• Diarrhea
• Rash
• Euphoria
• Ataxia (loss of balance)

Other important side effects include:

• Paradoxical reactions with excitability
• Muscle spasm
• Lack of sleep
• Rage
• Confusion
• Speech problems
• Double vision

Possible serious side effects:

• Respiratory depression
• Neutropenia
• Depression

Cyclobenzaprine

• The recommended dose of cyclobenzaprine dose is 5 or 10 mg three times daily using immediate release tablets or 15 or 30 mg once daily using extended release tablets.

Valium

• Diazepam may be taken with or without food.
• Diazepam is disposed of by the liver and excreted mainly by the kidney. Dosages of diazepam may need to be lowered in patients with abnormal kidney function.
• The usual oral diazepam dose for anxiety or seizures is 2-10 mg given 2-4 times daily.
• The usual rectal dose is 0.2-0.5 mg/kg and depends on the age of the patient.

Cyclobenzaprine

• Cyclobenzaprine is chemically related to the tricyclic class of antidepressants, for example, amitriptyline (Elavil, Endep), nortriptyline Pamelor). As such, it should not be taken with or within two weeks of any monoamine oxidase (MAO) inhibitor, for example, isocarboxazid (Marplan), phenelzine (Nardil), tranylcypromine (Parnate), and procarbazine (Matulane). High fever, convulsions, and even death can occur when these drugs are used together.
• Cyclobenzaprine interacts with other medications and drugs that slow the brain's processes, such as
  • alcohol,
  • barbiturates,
  • benzodiazepines, for example, diazepam (Valium), lorazepam (Ativan), and
  • narcotics.

Valium

Alcohol or medications that cause sedation may add to the sedative effects of diazepam. Patients taking benzodiazepines should avoid such combinations.

The following drugs may prolong the effects of diazepam by inhibiting liver enzymes that eliminate diazepam:

• cimetidine (Tagamet)
• ketoconazole (Nizoral)
• itraconazole (Sporanox)
• omeprazole (Prilosec, Rapinex)
• erythromycin
• clarithromycin (Biaxin)
• darunavir (Prezista)
• fluvoxamine (Luvox)
• fluoxetine (Prozac)

Dosages may need to be decreased when these drugs are used with diazepam.

Carbamazepine (Tegretol), rifampin (Rifadin), and St. John's Wort decrease levels of diazepam by increasing the elimination of diazepam by liver enzymes.

Cyclobenzaprine

• There are no adequate studies of cyclobenzaprine in pregnant women. However, studies in animals suggest no important effects on the fetus. Cyclobenzaprine therefore can be used in pregnancy if the physician feels that it is necessary.
• It is not known whether cyclobenzaprine is secreted in milk. However, since it is related to the tricyclic antidepressants, some of which are excreted in breast milk, caution is advised in using this medication in women who are breastfeeding.

Valium

• Benzodiazepines, including diazepam, can cause fetal abnormalities and should not be used during pregnancy.
• Diazepam is excreted in breast milk and can affect nursing infants. Therefore, diazepam should not be used by women who are nursing.