5500 WHITE PILL – IDENTIFICATION, MECHANISM OF ACTION, SIDE EFFECTS

The 5500 white pill (specifically debossed with imprint SB 5500) is Albenza (Albendazole 200 mg), manufactured by GlaxoSmithKline (originally SmithKline Beecham, hence the “SB” designation) and distributed by Impax/Amneal. Albendazole is a broad-spectrum, synthetic benzimidazole anthelmintic agent prescribed to treat tissue-invasive parasitic helminth infections. It is not a controlled substance.

Pill Identification & Physical Characteristics

Property – Description

• Brand / Generic Name – Albenza / Albendazole (200 mg)
• Imprint – SB above an embossed pentagon shape and 5500 below it; embossed pentagon on reverse
• Form & Color – Round, tilt-tab / chewable tablet; White to off-white
• Size – Approximately 13 mm in diameter
• Drug Class – Anthelmintic / Benzimidazole Derivative
• Manufacturer – GlaxoSmithKline / Impax Laboratories

Mechanism of Action

Albendazole exerts vermicidal, ovicidal, and larvicidal activity against helminths through degenerative alterations in cytoplasmic and microtubular structures:

• Inhibition of Tubulin Polymerization: Albendazole (and its primary active metabolite, albendazole sulfoxide) binds selectively to the colchicine-sensitive site of parasite tubulin. This prevents the polymerization of tubulin dimers into functional cytoplasmic microtubules.
• Disruption of Glucose Uptake & Energy Depletion: Microtubular loss impairs glucose uptake in the parasite’s intestinal and absorptive cells, depleting glycogen stores and inhibiting adenosine triphosphate production.
• Cellular Degeneration & Parasite Death: Deprived of energy reserves and unable to maintain cytoplasmic transport, the parasite is immobilized and undergoes cellular lysis, leading to clearance by the host immune system.

Indications & Dosage

Approved Indications

• Parenchymal Neurocysticercosis: Active central nervous system lesions caused by larval forms of the pork tapeworm (Taenia solium).
• Cystic Hydatid Disease (Echinococcosis): Larval cysts in the liver, lungs, or peritoneum caused by the dog tapeworm (Echinococcus granulosus).
• Common Off-Label Uses: Hookworm (Ancylostoma, Necator), ascariasis (roundworm), enterobiasis (pinworm), strongyloidiasis, cutaneous larva migrans, and microsporidiosis.

General Adult & Pediatric Dosing

• Neurocysticercosis:
• Patients : 400 mg orally twice daily with meals for 8 to 30 days.
• Patients : 15 kg day in two divided doses with meals for 8 to 30 days.

• Hydatid Disease:
• Given in 28-day treatment cycles, followed by a 14-day albendazole-free interval, repeated for a total of 3 cycles. Dosing mirrors the protocol.

• Administration Method:
• Tablets may be swallowed whole, crushed, or chewed with water.
• Food Dependency: Must be administered with fatty meals to achieve adequate systemic absorption (fat increases bioavailability up to 5-fold, which is critical for tissue-invasive infections like neurocysticercosis or echinococcosis).

Side Effects

Common Adverse Reactions

• Transient elevations in hepatic transaminases (ALT/AST)
• Abdominal pain, nausea, and vomiting
• Headaches and dizziness
• Reversible alopecia (thinning or loss of hair)
• Fever

Severe & Emergent Reactions

• Bone Marrow Suppression: Fatal granulocytopenia, pancytopenia, agranulocytosis, and aplastic anemia.
• Severe Hepatotoxicity: Acute hepatitis, jaundice, and severe transaminase elevations.
• Inflammatory Neurological Reactions: Increased intracranial pressure, seizures, and meningismus triggered by the inflammatory response to dying intracranial parasites.
• Severe Cutaneous Reactions: Stevens-Johnson Syndrome (SJS), Toxic Epidermal Necrolysis (TEN), and erythema multiforme.

Precautions & Drug Interactions

• Concomitant Corticosteroids & Anticonvulsants: When treating neurocysticercosis, patients must receive concurrent systemic corticosteroids (e.g., dexamethasone) to minimize cerebral edema caused by parasite death, along with anticonvulsants to prevent seizure spikes.
• Ophthalmological Examination: Prior to initiating therapy for neurocysticercosis, patients must undergo a thorough retinal exam to rule out intraocular / retinal cysticercosis, as drug-induced parasite death within the eye can cause permanent retinal damage or blindness.
• P-gp and CYP Inducers/Inhibitors: Dexamethasone, praziquantel, and cimetidine increase plasma concentrations of albendazole sulfoxide. Strong CYP inducers (e.g., carbamazepine, phenobarbital, phenytoin) decrease serum levels, reducing systemic efficacy.
• Regular Laboratory Monitoring: Complete blood counts (CBC) and liver function tests (LFTs) must be performed at baseline and every 2 weeks throughout active treatment cycles.

Critical Warnings

• Important Clinical Warnings:
• Bone Marrow Suppression: Albendazole can cause fatal bone marrow suppression. Discontinue treatment immediately if clinically significant reductions in blood cell counts occur.
• Teratogenicity & Pregnancy Warning: Albendazole is embryotoxic and teratogenic in animal models. It should not be administered to pregnant women except when no alternative therapy exists. Females of reproductive potential must have a negative pregnancy test prior to starting therapy and use effective barrier contraception during treatment and for at least 3 days following discontinuation.
• Pre-existing Hepatic Impairment: Patients with impaired liver function are at significantly increased risk of severe drug accumulation and hepatotoxicity.