Side Effects of Clarinex (desloratadine)

Clarinex(desloratadine) is a long-actingantihistamine化学similar toloratadine(他定) used to treatallergiesandhives(chronicurticaria) in adults and children 12 years of age and older.

Histamine is a chemical responsible for many of the signs and symptoms ofallergicreactions, for example, swelling of the lining of the nose,sneezing, anditchyeyes. Histamine is released from histamine-storing cells (mast cells) and then attaches to other cells that have receptors for histamine.

The attachment of the histamine to the receptors causes the cells to be "activated," releasing other chemicals which produce the effects that we associate withallergy. Clarinex blocks one type of receptor for histamine (the H1 receptor) and thus prevents activation of H1 receptor-containing cells by histamine. Clarinex does not readily enter the brain from the blood and, therefore, causes less drowsiness.

Common side effects of Clarinex include

• headache,
• dizziness,
• nausea,
• weakness,
• sore throat,
• dry mouth,
• muscle pain,
• painfulmenstruation, and
• sleepiness.

Drug interactionsof Clarinex includeketoconazole,erythromycin,azithromycin,fluoxetine, andcimetidine, which increase blood levels of Clarinex by reducing the elimination of Clarinex byliver enzymes.

Clarinex has not been studied inpregnantwomen. Clarinex passes intobreast milkand should be used with caution in women who are母乳喂养.

The most common side effects of desloratadine are:

• headache,
• dizziness,
• nausea,
• weakness,
• sore throat,
• dry mouth,
• musclepain,
• painfulmenstruation, and
• sleepiness.

The following adverse reactions are discussed in greater detail in other sections of the label:

• Hypersensitivity reactions.

Clinical Trials Experience

Becauseclinical trialsare conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in clinical practice.

Adults And Adolescents

Allergic Rhinitis

• In multiple-dose placebo-controlled trials, 2834 patients ages 12 years or older received Clarinex Tablets at doses of 2.5 mg to 20 mg daily, of whom 1655 patients received the recommended daily dose of 5 mg.
• In patients receiving 5 mg daily, the rate of adverse events was similar between Clarinex and placebo-treated patients.
• The percent of patients who withdrew prematurely due to adverse events was 2.4% in the Clarinex group and 2.6% in the placebo group.
• There were no serious adverse events in these trials in patients receiving desloratadine.
• All adverse events that were reported by greater than or equal to 2% of patients who received the recommended daily dose of Clarinex Tablets (5 mg once daily), and that were more common with Clarinex Tablets than placebo, are listed in Table 1.

Table 1: Incidence of Adverse Events Reported by ≥2% of Adult and AdolescentAllergic RhinitisPatients Receiving Clarinex Tablets

Adverse Event	Clarinex Tablets 5 mg (n=1655)	Placebo (n=1652)
Infections and Infestations
Pharyngitis	4.1%	2.0%
Nervous System Disorders
Somnolence	2.1%	1.8%
Gastrointestinal Disorders
Dry Mouth	3.0%	1.9%
Musculoskeletal and Connective Tissue Disorders
Myalgia	2.1%	1.8%
Reproductive System and Breast Disorders
Dysmenorrhea	2.1%	1.6%
General Disorders and Administration Site Conditions
Fatigue	2.1%	1.2%

• The frequency and magnitude of laboratory and electrocardiographic abnormalities were similar in Clarinex and placebo-treated patients.
• There were no differences in adverse events for subgroups of patients as defined by gender, age, or race.

Chronic Idiopathic Urticaria

• In multiple-dose, placebo-controlled trials of chronic idiopathicurticaria, 211 patients ages 12 years or older received Clarinex Tablets and 205 received placebo.
• Adverse events that were reported by greater than or equal to 2% of patients who received Clarinex Tablets and that were more common with Clarinex than placebo were (rates for Clarinex and placebo, respectively):
  • headache(14%, 13%),
  • nausea (5%, 2%),
  • fatigue(5%, 1%),
  • dizziness (4%, 3%),
  • pharyngitis(3%, 2%),
  • dyspepsia(3%, 1%), and
  • myalgia(3%, 1%).

Pediatrics

• Two hundred and forty-six pediatric subjects 6 months to 11 years of age received Clarinex Oral Solution for 15 days in three placebo-controlled clinical trials.
• Pediatric subjects aged 6 to 11 years received 2.5 mg once a day, subjects aged 1 to 5 years received 1.25 mg once a day, and subjects 6 to 11 months of age received 1.0 mg once a day.
• In subjects 6 to 11 years of age, no individual adverse event was reported by 2 percent or more of the subjects.
• In subjects 2 to 5 years of age, adverse events reported for Clarinex and placebo in at least 2 percent of subjects receiving Clarinex Oral Solution and at a frequency greater than placebo werefever(5.5%, 5.4%),urinary tract infection(3.6%, 0%) andvaricella(3.6%, 0%).
• In subjects 12 months to 23 months of age, adverse events reported for the Clarinex product and placebo in at least 2 percent of subjects receiving Clarinex Oral Solution and at a frequency greater than placebo were
  • fever(16.9%, 12.9%),
  • diarrhea(15.4%, 11.3%),
  • upper respiratory tract infections(10.8%, 9.7%),
  • coughing(10.8%, 6.5%),
  • appetite increased (3.1%, 1.6%),
  • emotional lability (3.1%, 0%),
  • epistaxis (3.1%, 0%),
  • parasitic infection (3.1%, 0%),
  • pharyngitis (3.1%, 0%),
  • rashmaculopapular (3.1%, 0%).
• In subjects 6 months to 11 months of age, adverse events reported for Clarinex and placebo in at least 2 percent of subjects receiving Clarinex Oral Solution and at a frequency greater than placebo were
  • upper respiratory tract infections(21.2%, 12.9%),
  • diarrhea(19.7%, 8.1%),
  • fever (12.1%, 1.6%),
  • irritability (12.1%, 11.3%),
  • coughing (10.6%, 9.7%),
  • somnolence (9.1%, 8.1%),
  • bronchitis(6.1%, 0%),
  • otitis media(6.1%, 1.6%),
  • vomiting(6.1%, 3.2%),
  • anorexia(4.5%, 1.6%),
  • pharyngitis (4.5%, 1.6%),
  • insomnia(4.5%, 0%),
  • rhinorrhea (4.5%, 3.2%),
  • erythema (3.0%, 1.6%), and
  • nausea (3.0%, 0%).
• There were no clinically meaningful changes in any electrocardiographic parameter, including the QTc interval.
• Only one of the 246 pediatric subjects receiving Clarinex Oral Solution in the clinical trials discontinued treatment because of an adverse event.

Post-Marketing Experience

Because adverse events are reported voluntarily from a population of uncertain size, it is not always possible to reliably estimate their frequency or establish a causal relationship to drug exposure. The following spontaneous adverse events have been reported during the marketing of desloratadine:

• Cardiac disorders:tachycardia,palpitations
• Respiratory, thoracic and mediastinal disorders:dyspnea
• Skin and subcutaneous tissue disorders:rash, pruritus
• Nervous system disorders:psychomotorhyperactivity, movement disorders (includingdystonia,tics, and extrapyramidal symptoms),seizures(reported in patients with and without a knownseizuredisorder)
• Immune system disorders:hypersensitivity reactions (such as urticaria,edemaandanaphylaxis)
• Investigations:elevatedliverenzymes includingbilirubin
• Hepatobiliary disorders:hepatitis
• 我tabolism andnutritiondisorders:increased appetite

Inhibitors Of Cytochrome P450 3A4

• In controlled clinical studies co-administration of desloratadine with ketoconazole, erythromycin, or azithromycin resulted in increased plasma concentrations of desloratadine and 3 hydroxydesloratadine, but there were no clinically relevant changes in the safety profile of desloratadine.

Fluoxetine

• In controlled clinical studies co-administration of desloratadine with fluoxetine, a selective serotonin reuptake inhibitor (SSRI), resulted in increased plasma concentrations of desloratadine and 3 hydroxydesloratadine, but there were no clinically relevant changes in the safety profile of desloratadine.

Cimetidine

• In controlled clinical studies co-administration of desloratadine with cimetidine, a histamine H2-receptor antagonist, resulted in increased plasma concentrations of desloratadine and 3 hydroxydesloratadine, but there were no clinically relevant changes in the safety profile of desloratadine.

Drug Abuse And Dependence

• There is no information to indicate that abuse or dependency occurs with Clarinex Tablets.