LEVOCETIRIZINE Drug Interactions: What You Need to Know

INTERACTIONS In vitro data indicate that levocetirizine is unlikely to produce pharmacokinetic interactions through inhibition or induction of liver drug-metabolizing enzymes. No in vivo drug-drug interaction studies have been performed with levocetirizine. Drug interaction studies have been performed with racemic cetirizine.

7.1 Antipyrine, Azithromycin, Cimetidine, Erythromycin, Ketoconazole, Theophylline, and Pseudoephedrine Pharmacokinetic interaction studies performed with racemic cetirizine demonstrated that cetirizine did not interact with antipyrine, pseudoephedrine, erythromycin, azithromycin, ketoconazole, and cimetidine. There was a small decrease (~ 16%) in the clearance of cetirizine caused by a 400 mg dose of theophylline. It is possible that higher theophylline doses could have a greater effect.

7.2 Ritonavir Ritonavir increased the plasma AUC of cetirizine by about 42% accompanied by an increase in half-life (53%) and a decrease in clearance (29%) of cetirizine. The disposition of ritonavir was not altered by concomitant cetirizine administration.

The use of levocetirizine dihydrochloride tablets are contraindicated in: Patients with known hypersensitivity to levocetirizine or any of the ingredients of levocetirizine , or to cetirizine. Observed reactions range from urticaria to anaphylaxis [see Adverse Reactions (6.2) ]. Patients with end-stage renal disease (CL CR < 10 mL/min) and patients undergoing hemodialysis. Pediatric patients 6 to 11 years of age with impaired renal function [see Use in Specific Populations (8.4) ]. Patients with a known hypersensitivity to levocetirizine or any of the ingredients of levocetirizine dihydrochloride or to cetirizine (4.1) Patients with end-stage renal disease at less than 10 mL/min creatinine clearance or patients undergoing hemodialysis (4.2)

Children

6 months to 11 years of age with renal impairment (4.3)

4.1 Patients with known hypersensitivity

• Patients with known hypersensitivity to levocetirizine or any of the ingredients of levocetirizine dihydrochloride, or to cetirizine. Observed reactions range from urticaria to anaphylaxis [see Adverse Reactions (6.2) ].

4.2 Patients with end-stage renal disease

• Patients with end-stage renal disease (CL CR < 10 mL/min) and patients undergoing hemodialysis.

4.3 Pediatric patients with impaired renal function Children 6 months to 11 years of age with impaired renal function

AND PRECAUTIONS Somnolence: Somnolence, fatigue, and asthenia have been reported with use of levocetirizine dihydrochloride tablets in some patients in clinical trials. Avoid engaging in hazardous occupations requiring complete mental alertness such as driving or operating machinery when taking levocetirizine dihydrochloride tablets. Avoid concurrent use of alcohol or other central nervous system depressants with levocetirizine dihydrochloride tablets. ( 5.1 )

Urinary

Retention: Urinary retention has been reported with use of levocetirizine dihydrochloride tablets. Use with caution in patients with predisposing factors of urinary retention (e.g. spinal cord lesion, prostatic hyperplasia). Discontinue levocetirizine dihydrochloride tablets if urinary retention occurs. ( 5.2 ) Risk of New Onset Pruritus After Discontinuation of Levocetirizine dihydrochloride tablets: New onset pruritus within a few days after discontinuation of Levocetirizine dihydrochloride tablets has been reported, usually after long-term use (e.g., few months to years) of Levocetirizine dihydrochloride tablets. Symptoms may improve with restarting or tapering Levocetirizine dihydrochloride tablets ( 5.3 ).

5.1 Somnolence In clinical trials the occurrence of somnolence, fatigue, and asthenia has been reported in some patients under therapy with levocetirizine dihydrochloride. Patients should be cautioned against engaging in hazardous occupations requiring complete mental alertness, and motor coordination such as operating machinery or driving a motor vehicle after ingestion of levocetirizine dihydrochloride. Concurrent use of levocetirizine dihydrochloride with alcohol or other central nervous system depressants should be avoided because additional reductions in alertness and additional impairment of central nervous system performance may occur.

5.2 Urinary Retention Urinary retention has been reported post marketing with levocetirizine dihydrochloride. Levocetirizine dihydrochloride should be used with caution in patients with predisposing factors of urinary retention (e.g. spinal cord lesion, prostatic hyperplasia) as levocetirizine dihydrochloride may increase the risk of urinary retention. Discontinue levocetirizine dihydrochloride if urinary retention occurs.

5.3 Risk of New Onset Pruritus After Discontinuation of Levocetirizine Dihydrochloride Tablets Cases of pruritus after discontinuation of levocetirizine dihydrochloride tablets have been reported in the postmarketing setting in patients where pruritus was not present before initiation of levocetirizine dihydrochloride tablets. Pruritus occurred within a few days of discontinuing levocetirizine dihydrochloride tablets among patients who used levocetirizine dihydrochloride tablets long-term (e.g., few months to years). Reported cases of pruritus were infrequent, but some were serious with patients experiencing widespread severe pruritus <span class="opacity-50 text-xs">[see Adverse Reactions (6.2) ]</span> . If pruritus occurs after discontinuation of levocetirizine dihydrochloride tablets, symptoms may improve with restarting or tapering levocetirizine dihydrochloride tablets.