This word document deals with the drug profile of albendazole. Important headings, with respect to its pharmacology, along with a note on important drug-related counselling tips for patients and health-care professionals have also been mentioned, with reference to standard textbooks, guidelines and relevant articles.

1. ALBENDAZOLE:
A. DRUG CLASS:Broad-spectrum anthelminthic (Benzimidazole)
B. MECHANISM OF ACTION: (Ref.: Goodman & Gilman, 13th ed., Pg.: 1001)
- Drug  binds to beta-tubulin of parasite  inhibits microtubule formation
- Drug  shows higher efficacy for parasite beta-tubulin, compared to that of humans
or higher eukaryotes  thus, results in selective toxicity!
- Other anthelminthic effects include:
1. Inhibition of mitochondrial fumarate reductase
2. Reduced glucose transport
3. Uncoupling of oxidative phosphorylation.
C. PHARMACOKINETIC PROFILE:(Ref.: Goodman & Gilman, 13th ed., Pg.: 1001)
- Variable absorption after oral drug administration
- Absorption  increases by presence of:
1. Fatty foods (increases absorption by 5 times) [Dayan, 2003]
2. Bile salts (to some extent).
- Drug  converted by liver to albendazole sulfoxide  shows excellent effects
(compared to that of mebendazole) against tissue-dwelling helminths!
- Metabolized by CYP3A4 enzymes (Nagy et al, 2002)
- Metabolites:
1. Consist of (+) & (-) enantiomers
2. (+) enantiomer  shows higher plasma drug concentration (C) values, and
excreted more slowly compared to that of (-) enantiomer (Marques et al, 1999).
- 70% PPB (Plasma protein binding) capacity (Marques et al, 1999).
- Half-life: 4-15 hours (Marques et al, 1999).
- Well-distributed into various tissues
- Excreted mainly in urine.

2. D. ADVERSEEFFECTS: (Ref.: Goodman & Gilman, 13th ed., Pg.: 1003; Katzung, 14th ed.,
Pg.: 940; Antibiotics manual: A guide to commonly used antimicrobials, Pg.: 3).
- Albendazole  if used for 1-3 days:
i. Free of clinically significant ADRs
ii. Mild & transient epigastric distress, diarrhea, headache, nausea, dizziness &
insomnia observed.
- Albendazole  if used for long-term:
i. Usually well-tolerated
ii. Abdominal distress, headaches, fever, fatigue, alopecia, etc. are observed.
- LIVER DYSFUNCTION:
i. Observed in >15% of patients
ii. Rise in serum transaminases observed
iii. Jaundice (Rarely)
iv. LFTs  tend to normalize after treatment is stopped
- With long-term use  bone marrow toxicity (granulocytopenia, agranulocytosis,
pancytopenia) can occur  warrants monitoring of CBC every 2 weeks!
E. DRUG INTERACTIONS: (Ref.: Katzung, 14th ed., Pg.: 940; Goodman & Gilman, 13th
ed., Pg.: 1001)
- Albendazole + dexamethasone, praziquantel & cimetidine  increased levels of
former
- Albendazole + ritonavir, phenytoin, phenobarbital & carbamazepine  reduced
levels of former
- Albendazole + grapefruit juice  increased bioavailability of former by 3.2 times!
- Albendazole + grapefruit juice  reduced half-life by 46%!

3. F. PREGNANCY STATUS: (Ref.: Goodman & Gilman, 13th ed., Pg.: 1003)
- Although albendazole is not recommended for use in pregnancy  according to a
review  use of albendazole during pregnancy was not associated with major
congenital defects!
- In pregnancy  with hookworm infections  high risk of iron-deficiency anemia 
high risk of morbidity!
- Taking the above into consideration  WHO has recommended that:
“Albendazole treatment can be initiated in pregnancy, provided that improved
iron status (due to elimination of hookworm infection) proves beneficial for both
mother & child”
- Albendazole is not recommended to be used in 1st trimester of pregnancy (can be
safely used in 2nd & 3rd trimesters!)
G. CONTRAINDICATIONS: (Ref.: Katzung, 14th ed., Pg.: 940; Goodman & Gilman, 13th
ed., Pg.: 1003)
- Known drug hypersensitivity
- Liver cirrhosis
- First trimester of pregnancy.
H. DOSAGEADJUSTMENTS FOR SPECIAL POPULATIONS: (Ref.: Antibiotics
manual: A guide to commonly used antimicrobials, Pg.: 3; Goodman & Gilman, 13th ed.,
Pg.: 1003)
1. IN RENAL IMPAIRMENT: Not required
2. IN HEPATIC IMPAIRMENT:
- Contraindicated in liver cirrhosis
- With extrahepatic obstruction  drug levels tend to rise, yet no dosage adjustment
is required.
3. IN PEDIATRICS:
- Safety not extensively studied in children below 2 years of age
- According to WHO guidelines  albendazole may be used in children of age less
than 1 year, if risks from STH (Soil-transmitted helminths) are justified
- For children between age 12-24 months  albendazole is given at a dose of 200 mg
orally.

4. I. ANTHELMINTHIC SPECTRUM: (Ref.: Antibiotics simplified, 4th edition, Pg.223)
Albendazole shows activity against:
1. Ascaris lumbricoides (Roundworm)
2. Enterobius vermicularis (Pinworm)
3. Necator americanus (Hookworm)
4. Stronglyoides stercoralis (Threadworm)
5. Echinococcus
6. Taenia solium.
J. INDICATIONS (CLINICAL USES): (Ref.: Katzung, 14th ed., Pg.: 939-940)
1. ASCARIASIS:
- For adults & children > 2 years old  dose of 400 mg orally, single dose is given, for
2-3 days
2. PINWORM:
- For adults & children > 2 years old  dose of 400 mg orally, single dose is given, for
2 weeks.
3. HOOKWORMINFECTIONS:
- Dose: 400 mg OD, for 3 days (preferred over mebendazole)
4. TRICHURIASIS:
- Focus on combination of either (albendazole / mebendazole + ivermectin) OR
(Albendazole + oxantel pamoate).
5. HYDATID DISEASE:
- Used as DOC (Drug of choice) & also as adjunct to surgical removal & aspiration of
cysts
- Dose: 400 mg BD, with meals, for 1 month or longer.

5. - According to another therapeutic strategy  the following method of treatment can
also be adopted:
Step 1: Use (albendazole + praziquantel) combination for 1 month
Step 2: Assess response after 1 month
Step 3: If response is positive  continue above treatment
OR
If response is negative  use combinative (surgical & drug treatment).
6. NEUROCYSTICERCOSIS:
- Since some anthelminthics can exacerbate neurologic disease in patients with
neurocysticercosis  role of medical therapy in treatment of the same is
controversial  thus treatment is restricted only for symptomatic parenchymal/
intraventricular cysts
- Corticosteroids  should be given along with albendazole to reduce inflammation
caused by dying organisms
- Albendazole is preferred over praziquantel for treatment of neurocysticercosis,
owing to the following reasons:
a. Shorter treatment course
b. Cost-effective
c. Improved penetration into subarachnoid space
d. High plasma drug concentration, when given along with corticosteroids (as
compared to that of praziquantel)
- Dose: 400 mg BD, for 3 weeks
- For multiple brain cysts  focus on the combination therapy of (albendazole+
praziquantel+ corticosteroid)!

6. 7. MISCELLANEOUS USES:
i. Cutaneous larva migrans (400 mg BD, for 3 days)
ii. Visceral larva migrans (400 mg BD, for 5 days)
iii. Intestinal capillariasis (400 mg OD, for 10 days)
iv. Microsporidial infections (400 mg BD, for 2 weeks or more)
v. Gnathostomiasis (400 mg BD, for 3 weeks)
vi. Taeniasis (400 mg BD, for 3 days)
vii. Trichinosis (400 mg BD, for 1-2 weeks)
viii. Clonorchiasis (400 mg BD, for 1 week).
K. IMPORTANTTIPS FOR HEALTHCAREPROFESSIONALS &PATIENTS: (Ref.:
Antibiotics manual: A guide to commonly used antimicrobials, Pg.: 4)
1. During treatment of neurocysticercosis  corticosteroids should be given along with
albendazole, to prevent risks of inflammation caused by dying organisms
2. Albendazole should be consumed along with food (especially fatty meal)
3. For children  albendazole pills should be crushed (since children will face issues in
swallowing tablets)
4. Monitoring parameters (while on therapy) include:
a. CBC
b. LFTs.