Usage
Diltiazem + Lidocaine is prescribed for the treatment of anal fissures. It is also used for hemorrhoids and other anal discomforts. This combination may also be considered, under the guidance of a healthcare professional, for other conditions involving muscle spasms and localized pain, such as with hemorrhoids.
Pharmacologically, Diltiazem is classified as a calcium channel blocker, and Lidocaine is a local anesthetic. They are usually compounded together for this indication in an ointment or cream.
Diltiazem works by relaxing the smooth muscles in the anal sphincter, reducing resting pressure and improving blood flow to promote healing. Lidocaine provides local pain relief.
Alternate Names
There are no officially recognized alternate names for the combination product. However, it may be referred to as Diltiazem/Lidocaine ointment/cream.
Brand names vary depending on the compounding pharmacy.
How It Works
Pharmacodynamics: Diltiazem, a calcium channel blocker, inhibits calcium influx into smooth muscle cells, causing vasodilation and reducing anal sphincter pressure. Lidocaine blocks sodium channels, inhibiting nerve impulse transmission and providing local anesthesia.
Pharmacokinetics: Both drugs are absorbed locally. When applied rectally, systemic absorption of Lidocaine is minimal. Diltiazem, even when applied topically, has the potential for systemic absorption although it would be expected to be much less than orally administered Diltiazem. Diltiazem is primarily metabolized by the liver (CYP3A4 enzyme) and excreted in the urine and feces. Lidocaine is also metabolized by the liver and excreted in the urine.
Mode of Action: Diltiazem’s vasodilatory effect increases blood flow to the anal fissure, promoting healing. Lidocaine’s anesthetic action relieves pain and discomfort associated with the fissure.
Receptor Binding/Enzyme Inhibition: Diltiazem blocks L-type calcium channels. Lidocaine blocks voltage-gated sodium channels.
Elimination Pathways: Diltiazem is primarily eliminated via hepatic metabolism (CYP3A4 enzymes) with renal and fecal excretion. Lidocaine is mainly eliminated through hepatic metabolism.
Dosage
Standard Dosage
Adults: A pea-sized amount of the ointment is typically applied intra-anally three times a day, often for six weeks, then reduced to once or twice daily for another six weeks. Some sources recommend insertion of the finger at least halfway into the rectum.
Special Cases:
- Elderly Patients: Dosage adjustments may be necessary due to age-related decline in hepatic and renal function. Start with a lower dose and titrate slowly. Elderly are at greater risk for dizziness and light-headedness and so caution and slow titration of dose is warranted.
- Patients with Renal Impairment: Exercise caution. Adjust dose based on the degree of impairment.
- Patients with Hepatic Dysfunction: Exercise caution. Reduce the dose as Diltiazem is metabolized by the liver.
- Patients with Comorbid Conditions: Consider underlying cardiovascular conditions and other medications the patient may be taking as interactions are possible.
Clinical Use Cases
Dosage and administration for intubation, surgical procedures, mechanical ventilation, and ICU use are not applicable to this combination, as it is intended for topical application for anal fissures.
Dosage Adjustments
Adjustments should be based on individual patient response and tolerance, as well as hepatic and renal function.
Side Effects
Common Side Effects:
Local reactions such as itching or burning at the application site, headache, nausea, dizziness, light-headedness
Rare but Serious Side Effects:
Severe dizziness, fainting, fast/pounding heartbeat, paleness, sweating, blurred vision, dry mouth, dark urine, bluish lips/skin/nails, unusual tiredness, severe weakness, seizures.
Long-Term Effects:
Data regarding chronic complications from prolonged use is limited.
Contraindications
Hypersensitivity to diltiazem or lidocaine, severe anemia, recent myocardial infarction or pulmonary congestion, concurrent use of rifampin. Pre-existing medical conditions, especially of the heart or liver, should be discussed with the prescriber.
Drug Interactions
Diltiazem interacts with several medications, including certain antihypertensives, antiarrhythmics, and CYP3A4 inhibitors and inducers (e.g., rifampin, phenytoin). Grapefruit juice can increase blood levels. Smoking may reduce the effectiveness of Lidocaine. Beta-blockers and antiarrhythmics can interact with Lidocaine. The interactions may vary depending on the dosage form and route of administration.
Pregnancy and Breastfeeding
Consult with a healthcare professional regarding the use of this medication during pregnancy and breastfeeding. Safety during pregnancy has not been well-established and risks should be carefully considered. Lidocaine appears to be safe while breastfeeding but it is recommended to wait an hour after applying ointment before breastfeeding.
Drug Profile Summary
- Mechanism of Action: Diltiazem: Calcium channel blocker causing vasodilation. Lidocaine: Local anesthetic blocking sodium channels.
- Side Effects: Itching, burning, headache, nausea, dizziness. Rarely: severe cardiovascular effects, seizures.
- Contraindications: Hypersensitivity, certain cardiac conditions, severe hepatic impairment, concurrent use of rifampin.
- Drug Interactions: CYP3A4 inhibitors/inducers, antihypertensives, antiarrhythmics.
- Pregnancy & Breastfeeding: Consult a healthcare professional.
- Dosage: Apply a pea-sized amount intra-anally three times daily, then reduce to once or twice daily.
- Monitoring Parameters: Blood pressure, heart rate, liver function tests (especially with prolonged use).
Popular Combinations
The combination of diltiazem and lidocaine is itself a common combination for anal fissures. No other particular additional medication combinations are widely established.
Precautions
- General Precautions: Evaluate patient’s medical history, including allergies and concurrent medications. Monitor for adverse reactions.
- Specific Populations: As discussed above, exercise caution in pregnant/breastfeeding women, children, and elderly patients, and those with hepatic/renal impairment.
- Lifestyle Considerations: Avoid alcohol and driving if experiencing dizziness or blurred vision.
FAQs (Frequently Asked Questions)
Q1: What is the recommended dosage for Diltiazem + Lidocaine?
A: Adults typically apply a pea-sized amount intra-anally three times daily initially, then reduce to once or twice daily as symptoms improve. Pediatric dosages should be determined by a doctor.
Q2: How does Diltiazem + Lidocaine work for anal fissures?
A: Diltiazem relaxes the anal sphincter to improve blood flow and promote healing, while lidocaine provides local pain relief.
Q3: What are the common side effects?
A: Itching or burning at the application site, headache, nausea, and dizziness can occur.
Q4: Are there any serious side effects I should be aware of?
A: Rarely, serious side effects like severe dizziness, fainting, irregular heartbeat, and allergic reactions can occur. Seek immediate medical attention if these develop.
Q5: Can pregnant or breastfeeding women use this medication?
A: Consult a healthcare professional before use during pregnancy or breastfeeding. Caution should be exercised.
Q6: What are the contraindications for Diltiazem + Lidocaine?
A: Contraindications include hypersensitivity to the components, severe anemia, certain heart conditions, and concomitant use of rifampin.
Q7: Does Diltiazem + Lidocaine interact with other medications?
A: Yes, potential interactions exist with certain antihypertensives, antiarrhythmics, and drugs metabolized by CYP3A4. Consult a healthcare professional regarding specific drug interactions.
Q8: How long does it typically take to see improvement with Diltiazem + Lidocaine?
A: Improvement can vary, but many patients experience relief within a few weeks of starting treatment. Full treatment can be as long as 12 weeks.
Q9: What should I do if I miss a dose?
A: Apply the missed dose as soon as you remember, unless it is close to the next scheduled dose. Do not double the dose.
Q10: Is surgery necessary for anal fissures?
A: Most anal fissures heal with conservative treatments like Diltiazem + Lidocaine. Surgery is usually reserved for chronic fissures that do not respond to medical therapy.
