Leukotriene inhibitors are associated with unusual weakness, upset stomach, earache, dizziness, cough, headache, trouble sleeping.

They don't relieve other allergy symptoms such as itching and sneezing.

Immunomodulators: These are topical medications used to treat skin allergies.

Topical immunomodulators for skin allergies may cause stinging, burning, irritation, and itching at the application site. Other drugs that cause drowsiness, such as sleeping medications, narcotic pain medications, sedatives, muscle relaxants, antidepressants and seizure medications.

Drugs with anticholinergic activity such as amitryptiline and other tricyclic antidepressants, antipsychotics like chlorpromazine, certain drugs to prevent vomiting (prochlorperazine and promethazine.

Nasal corticosteroids can cause nasal dryness or irritation, nosebleed, throat irritation, headache, nausea, vomiting, cough, and fungal infections of the throat with long-term use.

Mast cell stabilizers can cause a short-lived stinging sensation inside the nose.Drugs affecting metabolism of corticosteroids, such as ketoconazole (Nizoral, Xolegel, Extina, Ketoconazole Cream) and ritonavir (Kaletra Capsules, Kaletra Tablets, Norvir).Drugs that stimulate liver metabolism, such as phenytoin (Dilantin,) phenobarbital, and carbamazepine (Tegretol) – as well as the antibiotic Rifampin.They are often used if other agents are ineffective or intolerable.Autoinjectable epinephrine: This is used to treat a life-threatening allergic reaction known as anaphylaxis, which may be caused by severe allergic response to foods, drugs, or insect stings.Newer antihistamines are said to be non-sedating, although some users may experience drowsiness even from these.