Usage
- Medical Conditions: This combination is prescribed for the relief of abdominal pain and cramping associated with irritable bowel syndrome (IBS) and other functional gastrointestinal disorders. Diazepam is used for anxiety, muscle spasms, and seizures, while Dicyclomine targets smooth muscle spasms in the GI tract.
- Pharmacological Classifications: Diazepam is a benzodiazepine (anxiolytic, sedative, hypnotic, anticonvulsant, muscle relaxant), and Dicyclomine is an anticholinergic/antispasmodic.
- Mechanism of Action: Diazepam enhances the effect of GABA, an inhibitory neurotransmitter, leading to a calming effect on the central nervous system. Dicyclomine blocks the action of acetylcholine, a neurotransmitter that stimulates muscle contractions in the GI tract.
Alternate Names
- While “Diazepam + Dicyclomine” is the generic name, the combination is marketed under various brand names, including Decolic.
How It Works
- Pharmacodynamics: Diazepam acts on GABA receptors in the central nervous system, promoting relaxation and reducing anxiety, muscle spasms, and seizure activity. Dicyclomine acts on muscarinic receptors in the GI tract, inhibiting smooth muscle contractions and reducing cramping and pain.
- Pharmacokinetics:
- Diazepam: Diazepam is well-absorbed orally and undergoes hepatic metabolism, primarily by CYP3A4 and CYP2C19 enzymes. It has a long half-life due to active metabolites. Elimination is mainly through renal excretion.
- Dicyclomine: Dicyclomine is also well-absorbed orally. Metabolism and elimination pathways are not as extensively characterized as diazepam, but some hepatic metabolism is expected. Excretion is likely through both renal and biliary routes.
- Mode of Action: Diazepam binds to benzodiazepine receptors, which are part of the GABA receptor complex. This binding potentiates the inhibitory effects of GABA, resulting in reduced neuronal excitability. Dicyclomine competitively blocks muscarinic receptors in the GI smooth muscle, preventing acetylcholine from binding and initiating muscle contractions.
Dosage
Standard Dosage
Adults:
- Diazepam: 2-10 mg orally, 2-4 times daily, adjusted as needed. Dicyclomine: 20-40 mg orally, up to four times a day. The combined dose is usually 2 mg of diazepam and 20 mg of dicyclomine taken together three to four times a day. Maximum dose for dicyclomine is 160 mg per day.
Children:
- This combination is generally not recommended for children under six months of age. The dosage for older children should be determined by a pediatrician and be individualized based on weight, age, and medical condition.
Special Cases:
- Elderly Patients: Start with the lowest effective dose and titrate cautiously due to increased sensitivity to side effects.
- Patients with Renal Impairment: Dose adjustments may be necessary; close monitoring is recommended.
- Patients with Hepatic Dysfunction: Dose reduction is typically required due to impaired metabolism.
- Patients with Comorbid Conditions: Careful consideration is needed for patients with glaucoma, myasthenia gravis, urinary or GI obstruction, severe ulcerative colitis, reflux esophagitis, cardiovascular disease, etc.
Clinical Use Cases
- The use of this combination in clinical settings like intubation, surgical procedures, mechanical ventilation, ICU use, and emergency situations is not routinely indicated. Diazepam may be used individually in such settings for specific indications (e.g., status epilepticus, pre-operative sedation).
Dosage Adjustments
- Dosage adjustments should be based on individual patient response, tolerability, and the presence of renal or hepatic impairment. Therapeutic drug monitoring may be helpful in optimizing therapy.
Side Effects
Common Side Effects
- Dry mouth, blurred vision, dizziness, drowsiness, constipation, nausea, urinary retention, headache, nervousness, confusion, and fatigue.
Rare but Serious Side Effects
- Allergic reactions (rash, itching, swelling), difficulty breathing, irregular heartbeat, severe dizziness or fainting, hallucinations, psychosis, severe abdominal pain, and paralytic ileus.
Long-Term Effects
- Cognitive impairment, dependence (with diazepam), tolerance (with diazepam), and anticholinergic toxicity (with chronic dicyclomine use).
Adverse Drug Reactions (ADR)
- Severe allergic reactions (anaphylaxis), cardiac arrhythmias, acute glaucoma, paralytic ileus, respiratory depression, and seizures.
Contraindications
- Hypersensitivity to diazepam or dicyclomine, angle-closure glaucoma, myasthenia gravis, obstructive uropathy, obstructive gastrointestinal disorders (e.g., paralytic ileus, severe ulcerative colitis, toxic megacolon), unstable cardiovascular status, infants under 6 months of age, and breastfeeding mothers.
Drug Interactions
- Diazepam and dicyclomine both interact with numerous medications. Concomitant use with other CNS depressants (e.g., alcohol, opioids, antihistamines) may potentiate sedation and respiratory depression. Dicyclomine can interact with other anticholinergic drugs, increasing the risk of anticholinergic side effects. Both drugs can affect the absorption and metabolism of other medications. Specific examples include:
- Alcohol
- Antihistamines
- Opioids
- Glaucoma medications (e.g., Timolol)
- Antipsychotics (e.g., Chlorpromazine)
- Antidepressants (e.g., Amitriptyline)
- Digoxin.
Pregnancy and Breastfeeding
- Pregnancy: Diazepam is a pregnancy category D drug; it can cause birth defects and should be avoided during pregnancy, especially in the first trimester. Dicyclomine is a pregnancy category B drug; its safety in pregnancy has not been fully established. Use only if clearly needed and under close medical supervision.
- Breastfeeding: Both diazepam and dicyclomine pass into breast milk and can cause adverse effects in the infant. Breastfeeding is contraindicated while taking these medications.
Drug Profile Summary
- Mechanism of Action: Diazepam enhances GABAergic activity; dicyclomine blocks muscarinic receptors.
- Side Effects: Dry mouth, dizziness, drowsiness, blurred vision, constipation, nausea, urinary retention, confusion. Serious side effects include allergic reactions, arrhythmias, and hallucinations.
- Contraindications: Angle-closure glaucoma, myasthenia gravis, GI/urinary obstruction, infants under 6 months, breastfeeding.
- Drug Interactions: CNS depressants, anticholinergics, numerous other drugs (see detailed section above).
- Pregnancy & Breastfeeding: Contraindicated.
- Dosage: Adults: Diazepam 2-10 mg 2-4 times/day, dicyclomine 20-40 mg up to 4 times/day. Adjust for elderly and hepatic/renal impairment.
- Monitoring Parameters: Vital signs, mental status, GI function, and signs of anticholinergic toxicity.
Popular Combinations
- While diazepam and dicyclomine are sometimes prescribed together, information about other popular combinations with this specific mix is limited. Each drug individually may be combined with other medications for respective indications.
Precautions
- General Precautions: Monitor for side effects, especially in elderly patients. Caution in patients with hepatic or renal impairment, cardiovascular disease, or a history of drug dependence.
- Specific Populations: See “Special Cases” under Dosage.
- Lifestyle Considerations: Avoid alcohol and activities requiring alertness due to sedative effects.
FAQs (Frequently Asked Questions)
Q1: What is the recommended dosage for Diazepam + Dicyclomine?
A: The typical adult dose is 2 mg of diazepam and 20 mg of dicyclomine, taken three to four times daily. Dosages should be adjusted based on individual patient factors, as noted earlier.
Q2: Can this combination be used during pregnancy?
A: No, both diazepam and dicyclomine are contraindicated during pregnancy due to potential risks to the fetus.
Q3: What are the primary side effects to watch out for?
A: Common side effects include dry mouth, blurred vision, dizziness, drowsiness, constipation, and urinary retention.
Q4: What are the key drug interactions with Diazepam + Dicyclomine?
A: Significant interactions occur with other CNS depressants (alcohol, opioids, antihistamines), anticholinergics, and several other medications. Consult drug interaction resources for a complete list.
Q5: Can this combination be used in patients with glaucoma?
A: No, angle-closure glaucoma is a contraindication to the use of dicyclomine.
Q6: What is the mechanism of action of dicyclomine?
A: Dicyclomine is an anticholinergic that blocks muscarinic receptors in the GI tract, reducing smooth muscle spasms.
A: Diazepam is primarily metabolized in the liver by CYP3A4 and CYP2C19 enzymes.
Q8: Are there any long-term risks associated with this combination?
A: Yes, long-term use of diazepam can lead to dependence and tolerance. Chronic dicyclomine use can potentially cause anticholinergic toxicity.
Q9: What should I do if a patient experiences an allergic reaction?
A: Discontinue the medication immediately and provide appropriate medical care, including antihistamines, corticosteroids, and/or epinephrine, as necessary.
Q10: Can this combination be used in elderly patients?
A: Yes, but it should be used with caution. Start with a low dose and titrate gradually, monitoring closely for side effects. Dose adjustments might be necessary based on the patient’s condition.
