Usage
Albendazole + Pyrantel Pamoate is prescribed for the treatment of various parasitic worm infections, including:
- Enterobiasis (Pinworm Infection): Caused by Enterobius vermicularis.
- Ascariasis (Roundworm Infection): Caused by Ascaris lumbricoides.
- Hookworm Infection: Caused by Necator americanus and Ancylostoma duodenale.
- Trichuriasis (Whipworm infection): Caused by Trichuris trichiura
Pharmacological Classification: Anthelmintic (Antiparasitic)
Mechanism of Action: This combination exerts its anthelmintic effect through two distinct mechanisms:
- Albendazole: Inhibits microtubule synthesis in parasitic worms, disrupting their nutrient absorption and leading to their death.
- Pyrantel Pamoate: Acts as a depolarizing neuromuscular blocking agent, causing spastic paralysis of susceptible nematodes.
Alternate Names
No widely recognized alternate names exist for this specific combination. However, the individual components have other names:
- Albendazole: Sometimes referred to as albendazolum.
- Pyrantel Pamoate: Sometimes referred to as pyrantel embonate.
Brand Names: This combination may be marketed under various brand names depending on the region and manufacturer.
How It Works
Pharmacodynamics: Albendazole inhibits tubulin polymerization in helminths, disrupting their metabolic processes and ultimately causing their demise. Pyrantel pamoate acts as a depolarizing neuromuscular blocking agent, resulting in spastic paralysis of the worms. This paralysis facilitates their expulsion from the gastrointestinal tract.
Pharmacokinetics:
- Albendazole: Poorly absorbed orally, but its absorption is enhanced when taken with fatty meals. Metabolized extensively in the liver to its active metabolite, albendazole sulfoxide. Excreted primarily in bile and feces.
- Pyrantel Pamoate: Poorly absorbed from the gastrointestinal tract. The majority of the drug is excreted unchanged in feces, with a small amount excreted in urine.
Mode of Action:
- Albendazole: Binds to β-tubulin in helminths, preventing its polymerization into microtubules. This disrupts crucial cellular processes, including nutrient absorption, intracellular transport, and cell division, eventually leading to the worm’s death.
- Pyrantel Pamoate: Acts as a nicotinic acetylcholine receptor agonist at the neuromuscular junction of susceptible nematodes. This causes depolarization of the muscle cell membrane, leading to spastic paralysis.
Elimination Pathways:
- Albendazole: Primarily biliary and fecal excretion.
- Pyrantel Pamoate: Primarily fecal excretion, with minor renal excretion.
Dosage
Standard Dosage
Adults: A single dose of 400 mg Albendazole combined with Pyrantel Pamoate 11 mg/kg (up to a maximum of 1 g). The dose may be repeated in 2 weeks, especially for pinworm infections.
Children: Dosage is weight-based. Albendazole 400 mg (or 200 mg for children under 2 years) is given with Pyrantel Pamoate 11 mg/kg (up to a maximum of 1g) as a single dose. Pediatric safety considerations highlight the importance of accurate weight-based dosing. This combination is generally not recommended for children under 2 years of age unless specifically directed by a physician.
Special Cases:
- Elderly Patients: No specific dose adjustments based on age are recommended for the elderly.
- Patients with Renal Impairment: No dose adjustments are necessary for patients with renal impairment.
- Patients with Hepatic Dysfunction: Albendazole should be used cautiously with liver function monitoring. Dose reduction may be considered in patients with severe hepatic impairment.
- Patients with Comorbid Conditions: No specific dose adjustments are routinely recommended, but clinical judgment is necessary based on individual patient factors.
Clinical Use Cases
The use of this combination is limited to the treatment of helminthic infections. It’s not indicated for intubation, surgical procedures, mechanical ventilation, ICU use, or emergency situations.
Dosage Adjustments
Dosage adjustments may be required based on patient-specific factors such as hepatic dysfunction, but are not typically needed for renal impairment.
Side Effects
Common Side Effects:
- Nausea
- Vomiting
- Abdominal pain/cramps
- Diarrhea
- Headache
- Dizziness
- Drowsiness
- Insomnia
- Loss of appetite
Rare but Serious Side Effects:
- Liver dysfunction (elevated liver enzymes)
- Bone marrow suppression (leukopenia, thrombocytopenia, pancytopenia)
- Allergic reactions (rash, urticaria, Stevens-Johnson syndrome)
Long-Term Effects:
Chronic complications from short-term use are uncommon.
Adverse Drug Reactions (ADR):
Significant ADRs include severe allergic reactions, hepatotoxicity, and myelosuppression, requiring immediate medical attention.
Contraindications
- Hypersensitivity to albendazole, pyrantel pamoate, or any component of the formulation.
- Pregnancy (especially first trimester for albendazole).
- Severe malnutrition and anemia (for pyrantel pamoate).
- Intestinal obstruction.
Drug Interactions
- Albendazole: May interact with praziquantel (increased albendazole levels), cimetidine (increased albendazole sulfoxide levels), dexamethasone (increased albendazole levels), and anticonvulsants (altered metabolism).
- Pyrantel Pamoate: May interact with piperazine (antagonistic effects) and theophylline (increased theophylline levels).
Pregnancy and Breastfeeding
- Albendazole: Contraindicated in pregnancy, particularly during the first trimester. Use with caution during breastfeeding, though limited data suggest minimal risk.
- Pyrantel Pamoate: Generally considered safe during pregnancy and breastfeeding, though data are limited. Weigh the benefits against potential risks.
Drug Profile Summary
- Mechanism of Action: Albendazole: Inhibits microtubule synthesis. Pyrantel Pamoate: Neuromuscular blocking agent causing spastic paralysis.
- Side Effects: Nausea, vomiting, abdominal pain, headache, dizziness. Rarely: liver dysfunction, bone marrow suppression.
- Contraindications: Hypersensitivity, pregnancy (albendazole), intestinal obstruction.
- Drug Interactions: Albendazole: praziquantel, cimetidine, dexamethasone. Pyrantel Pamoate: piperazine, theophylline.
- Pregnancy & Breastfeeding: Albendazole: Avoid in pregnancy. Caution in breastfeeding. Pyrantel Pamoate: Generally safe.
- Dosage: Adults: 400 mg albendazole + 11 mg/kg pyrantel pamoate. Children: Weight-based dosing.
- Monitoring Parameters: Liver function tests (especially with albendazole), complete blood count (with prolonged albendazole use).
Popular Combinations
Albendazole and Pyrantel Pamoate are often combined due to their synergistic effects against multiple helminths.
Precautions
- General Precautions: Evaluate for pre-existing conditions, allergies, and potential drug interactions.
- Specific Populations: Caution in patients with hepatic dysfunction. Avoid albendazole in pregnancy.
- Lifestyle Considerations: No specific lifestyle restrictions are associated with this drug combination.
FAQs (Frequently Asked Questions)
Q1: What is the recommended dosage for Albendazole + Pyrantel Pamoate?
A: Adults: Albendazole 400 mg + Pyrantel Pamoate 11 mg/kg (max 1 g) as a single dose. Children: Weight-based dosing; consult pediatric guidelines. Repeat dose in 2 weeks, especially for pinworm.
Q2: What are the common side effects?
A: Nausea, vomiting, abdominal pain/cramps, diarrhea, headache, dizziness.
Q3: Is this combination safe during pregnancy?
A: Albendazole is contraindicated during pregnancy, especially the first trimester. Pyrantel Pamoate is generally considered safe, but consult guidelines.
Q4: What if a dose is missed?
A: Take the missed dose as soon as possible unless it’s close to the next scheduled dose. Do not double the dose.
Q5: How does this combination work?
A: Albendazole disrupts worm metabolism. Pyrantel Pamoate paralyzes them, allowing expulsion.
Q6: What infections does it treat?
A: Pinworm, roundworm, hookworm, and whipworm infections.
Q7: Are there any serious side effects?
A: Rarely: Liver problems, bone marrow suppression, and allergic reactions. Seek immediate medical attention if these occur.
Q8: Can it be used in patients with liver disease?
A: Albendazole should be used cautiously in patients with liver disease. Monitor liver function. Pyrantel Pamoate use should be physician-directed in these patients.
Q9: What are the drug interactions I should be aware of?
A: Albendazole interacts with praziquantel, cimetidine, dexamethasone, and some anticonvulsants. Pyrantel interacts with piperazine and theophylline.
Q10: How long does the treatment last?
A: Usually a single dose or up to 3 days, sometimes repeated in two weeks. Duration for hydatid disease and neurocysticercosis is longer; consult guidelines.
