Loratadine is an antihistamine also known as an antipruritic agent. Pruritus means itchiness. It blocks the histamine 1 receptors to prevent the effects of histamines after it has been released from mast cells. Histamine is a chemical substance which is responsible for vasodilation and increase blood flow to any injured area resulting to congestion, edema or swelling and redness otherwise known as the four hallmarks of inflammation (rubor- redness, calor-heat or increase warmth, dolor-pain and tumor- swelling or edema). Histamine is released from mast cells once an individual is exposed to an allergen ( a mild antigen). Antigen binds to the immunoglobulin E (IgE) forming an antigen-antibody complex then adheres to the mast cell surface leading to release of histamine. Severe form of allergic reaction known as anaphylaxis is life threatening especially if there’s closing of the throat and eventually anaphylactic shock because of generalized vasodilation.
Indications: relief of symptoms and signs of chronic urticaria (hives) and other allergic dermatologic or inflammatory disorders; for relief of symptoms associated with allergic rhinitis e.g. sneezing, runny nose (rhinorrhea) or nasal discharge and itching; also for ocular itchiness, burning and watering of the eyes.
Special precautions: Renal & hepatic insufficiency. Allergic reaction to antihistamines. Loratadine cause dizziness or drowsiness so use with caution when driving, operating machinery or performing other hazardous activities which requires to be fully alert. You may require a dosage adjustment or special monitoring during treatment if you have any liver or renal impairment. Individuals with phenylketonuria may need to monitor their intake of this particular brand of loratadine, the Alavert orally-disintegrating tablets which contain 8.4 mg of phenylalanine per tablet. Loratadine is not expected to harm an unborn baby (US FDA pregnancy category B) but this drug passes intro breast milk and may affect a nursing infant. Inform your doctor before taking loratadine if you are breastfeeding.
Do not take a double dose of this medication. It is usually taken once a day. Seek emergency consult if you experience symptoms of suspected loratadine overdose such as headache, drowsiness, irregular heartbeat, nausea, and vomiting
Serious adverse reactions: an allergic reaction (difficulty of breathing, closing of the throat, swelling of the lips, tongue, or face and wheals/hives); an irregular heartbeat (arrhythmia) or seizures. Other less serious side effects which may be more likely to occur are: drowsiness or dizziness, headache, nervousness, nausea, diarrhea, or abdominal discomfort, dry mouth, dry skin or itchiness or discoloration of urine.
There are no known interactions between loratadine and other medications. Talk to your doctor and pharmacist before taking any prescription or over-the-counter medicines, including vitamins, minerals, and herbal products, during treatment with loratadine.
Loratadine is a white to off-white powder not soluble in water, but very soluble in acetone, alcohol, and chloroform. It has a molecular weight of 382.89, and empirical formula of C22H23ClN2O2; its chemical name is ethyl4-(8-chloro-5,6-dihydro- 11H-benzo[5,6]cyclohepta[1,2-b] pyridin-11-ylidene)-1- piperidinecarboxylate. Claritin tablets contain 10 mg micronized loratadine, an antihistamine, to be administered orally. They also contain the following inactive ingredients: Corn starch, lactose, and magnesium stearate.
Loratadine has the following structural formula: