Montelukast Sodium (montelukast sodium)

Dosage of montelukast sodium is expressed in terms of montelukast.

Limited evidence in patients with mild to moderate hepatic impairment and clinical evidence of cirrhosis indicate that area under the plasma concentration-time curve (AUC) of montelukast is increased 41% and plasma montelukast elimination half-life is prolonged in these patients relative to patients with normal hepatic function. However, the manufacturer makes no specific recommendations for adjustment of montelukast dosage in patients with mild to moderate hepatic impairment. The pharmacokinetics of montelukast in patients with severe hepatic impairment or with hepatitis have not been evaluated.

The manufacturer makes no specific recommendations for dosage adjustment in patients with renal impairment. The drug is extensively metabolized and excreted principally in feces.

In patients with asthma with or without coexisting allergic rhinitis, montelukast is administered orally as a single daily dose in the evening. Safety and efficacy of montelukast in the management of asthma were established in clinical trials in which the drug was administered in the evening without regard to meals in adults, adolescents, and children 2-14 years of age. Evening dosing has been employed so that achievement of peak plasma concentrations of the drug might coincide with peak airway reactivity in the morning. In patients with allergic rhinitis, the time of administration may be individualized to suit patient needs. Efficacy was demonstrated in patients with seasonal allergic rhinitis when montelukast was administered in the morning or evening without regard to food intake.

Pharmacokinetic and clinical data support use of the 10-mg film-coated tablet of montelukast in adults and adolescents 15 years of age or older, use of the 5-mg chewable tablet in children 6-14 years of age, use of the 4-mg chewable tablet or 4-mg oral granules formulation in children 2-5 years of age, and use of the 4-mg oral granules formulation in infants and children 12-23 months of age for the treatment of asthma and in infants and children 6-23 months of age for the treatment of perennial allergic rhinitis.

Oral granules may be administered orally alone (directly in the mouth) or mixed with 1 teaspoonful (5 mL) of cold or room temperature baby formula or breast milk, or a spoonful of cold or room temperature soft food (applesauce, carrots, rice, or ice cream only); the stability of the drug when mixed with other foods has not been determined. Oral granules are not intended to be dissolved in any liquid other than baby formula or breast milk prior to administration. However, liquids may be taken subsequent to administration, and oral granules can be administered without regard to meals. The packet should not be opened until ready to use. After opening the packet of granules, patients should receive the full dose within 15 minutes; do not store the opened packet or mixtures of the drug with food, breast milk, or baby formula. Any unused portions should be discarded.

Montelukast has been used concomitantly in clinical studies with other drugs used routinely for the prevention and long-term symptomatic management of asthma without an apparent increase in adverse effects. In addition, montelukast has been used concomitantly with benzodiazepines, decongestants, nonsteroidal anti-inflammatory agents (NSAIAs), sedative-hypnotics, or thyroid hormones without evidence of an increase in adverse effects.

In drug-interaction studies, usual dosages of montelukast did not have clinically important effects on the pharmacokinetics of theophylline, warfarin, terfenadine (no longer commercially available in the US), digoxin, oral contraceptives (ethinyl estradiol with norethindrone), prednisone, or prednisolone.

Contraindicated Drug Combination: This drug combination is contraindicated and generally should not be dispensed or administered to the same patient.

Cyp1a2 Inducers/Florquinitau F-18

SEVERITY LEVEL: 1-Contraindicated Drug Combination: This drug combination is contraindicated and generally should not be dispensed or administered to the same patient.

MECHANISM OF ACTION: Florquinitau F-18 is a CYP1A2 substrate. CYP1A2 inducers may decrease the florquinitau F-18 parent fraction in plasma and reduce brain regional signal intensity.(1)

CLINICAL EFFECTS: Concurrent or recent use of CYP1A2 inducers with florquinitau F-18 may interfere with the interpretation of imaging results using fluoroestradiol F-18.(1)

PREDISPOSING FACTORS: None determined.

PATIENT MANAGEMENT: The manufacturer of florquinitau F-18 states use of CYP1A2 inducers should be avoided. Patients should stop CYP1A2 inducers at least 7 days prior to diagnostic testing with florquinitau F-18.(1)

DISCUSSION: Florquinitau F-18 is a CYP1A2 substrate. CYP1A2 inducers may decrease the florquinitau F-18 parent fraction in plasma and reduce brain regional signal intensity.(1) CYP1A2 inducers linked include: aminoglutethimide, asciminib, carbamazepine, fosphenytoin, leflunomide, marijuana smoking, montelukast, moricizine, nelfinavir, olverembatinib, omeprazole, phenobarbital, phenytoin, primidone, rifampin, ritonavir, teriflunomide, and valproic acid.(2,3)

There are no severe interactions for this drug.

There are no moderate interactions for this drug.

There is no enhanced messaging for this drug.

There are no contraindication contraindications for this drug.

• Depression
• Suicidal ideation

• Aggressive behavior
• Cutaneous vasculitis
• Eosinophilia
• Phenylketonuria

There is no enhanced messaging for this drug.

More Frequent

• Abnormal hepatic function tests
• Influenza

Less Frequent

• Bronchitis
• Infectious gastroenteritis
• Myopia
• Skin and skin structure infection

Rare or Very Rare

• Angioedema
• Chickenpox
• Cholestatic hepatitis
• Conjunctivitis
• Eosinophilia
• Eosinophilic granulomatosis with polyangiitis
• Eosinophilic pneumonia
• Epistaxis
• Erythema multiforme
• Erythema nodosum
• Gastroenteritis
• Hepatocellular damage
• Hostility
• Hypersensitivity angiitis
• Hypersensitivity drug reaction
• Jaundice
• Night terror
• Pancreatitis
• Pneumonia
• Pyuria
• Seizure disorder
• Stevens-johnson syndrome
• Suicidal
• Suicidal ideation
• Thrombocytopenic disorder
• Toxic epidermal necrolysis
• Urticaria

More Frequent

• Acute abdominal pain
• Cough
• Diarrhea
• Fever
• Headache disorder
• Otitis
• Pharyngitis
• Rhinorrhea
• Sinusitis
• Upper respiratory infection

Less Frequent

• Acute bacterial otitis media
• Atopic dermatitis
• Dizziness
• Fatigue
• General weakness
• Nasal congestion
• Skin rash
• Toothache

Rare or Very Rare

• Acute cognitive impairment
• Aggressive behavior
• Agitation
• Arthralgia
• Bruising
• Cramps
• Depression
• Disturbance of attention
• Dream disorder
• Drowsy
• Dyspepsia
• Eczema
• Edema
• Hallucinations
• Hypoesthesia
• Insomnia
• Irritability
• Laryngitis
• Memory impairment
• Motor tic disorder
• Myalgia
• Nausea
• Nervousness
• Nightmares
• Obsessive-compulsive disorder
• Palpitations
• Paresthesia
• Pruritus of skin
• Sleep disorder
• Sleep walking disorder
• Stuttering
• Symptoms of anxiety
• Tremor
• Urinary incontinence
• Viral infection
• Vomiting

No enhanced messaging available.

No enhanced messaging available.

Montelukast crosses the placenta following oral dosing in rats and rabbits. Reproduction studies in rats using oral dosages up to 400 mg/kg daily (estimated exposure approximately 100 times the AUC for adults at the maximum recommended daily oral dose) and in rabbits using oral dosages up to 300 mg/kg daily (estimated exposure approximately 110 times the AUC for adults at the maximum recommended daily oral dose) have not revealed evidence of harm to the fetus.

There are no adequate and well-controlled studies to date using montelukast in pregnant women, and the manufacturer states that montelukast should be used during pregnancy only when clearly needed. The American College of Obstetricians and Gynecologists (ACOG) generally recommends use of leukotriene modifiers as an alternative to a long-acting beta2-agonist in pregnant women with moderate persistent asthma who are inadequately controlled with low to medium dosages of an inhaled corticosteroid. (See Uses: Asthma.)

During postmarketing experience with montelukast, congenital limb defects have been reported rarely in the children of women treated with the drug; however, most of these women were receiving other antiasthmatic agents during their pregnancies. A causal relationship between montelukast use and the development of these congenital anomalies has not been established. The manufacturer maintains a registry to monitor pregnancy outcomes in women exposed to montelukast during pregnancy. Patients may be enrolled by calling 800-986-8999.

Montelukast is distributed into milk in rats. Since it is not known whether montelukast is distributed in human milk, the drug should be used with caution in nursing women.

No enhanced messaging available.