Fexofenadine use is not generally associated with liver enzyme elevations but terfenadine, a second generation antihistamine that is metabolized in part to fexofenadine, was the attributed cause of several reported cases of clinically apparent liver injury.
Non-sedating antihistamines can rarely cause acute liver injury. Although the liver damage is typically mild, if it occurs, antihistamines should be stopped. The liver function is usually only slightly deranged, and returns to normal with substitution of another antihistamine or cessation of the therapy.
Diphenhydramine is a first generation antihistamine that is used for symptoms of allergic rhinitis and the common cold. It is also commonly used as a mild sleeping aid. Diphenhydramine has not been linked to instances of clinically apparent acute liver injury.
Cetirizine and levocetirizine use are not generally associated with liver enzyme elevations, but have been linked to rare instances of clinically apparent liver injury.
Fexofenadine is unlikely to do you any harm if you take it for a long time. But it's best to take it only for as long as you need to. It's best not to drink alcohol while you're taking fexofenadine as it can make you feel sleepy.
If you take too many tablets, contact your doctor or the nearest hospital emergency department immediately. Symptoms of an overdose in adults are dizziness, drowsiness, fatigue and dry mouth. Do not take a double dose to make up for a forgotten tablet. Take the next dose at the usual time as prescribed by your doctor.
Long term use of some antihistamines may increase your risk of dementia. Diphenhydramine (Benadryl®) blocks the effects of a neurotransmitter called acetylcholine. This neurotransmitter is vital for memory and learning.
These results suggest that H1-antihistamines increase the progression of fatty liver disease in wild-type mice, and there seems to be an association between the severity of disease, presence of ApoE, and increase in hepatic bile acid levels.
Histamine Stimulates Liver OEA Biosynthesis via H1 Receptor Activation To further test this idea, we examined whether pharmacological blockade of histamine receptors affects liver OEA formation. His- tamine activates with submicromolar potencies four G protein- coupled receptors, termed H1 to H4 (Bongers et al., 2010).
Allergists recommend long-acting, non-sedating antihistamines — ones that won't make you sleepy — for everyday use. Though you may know them by their brand names, the generic versions tackle the same problems: Cetirizine (Zyrtec®, Aller-Tec®, Wall-Zyr®). Fexofenadine (Allegra®, Aller-ease®, Aller-Fex®, Wal-Fex®).
Loratadine—present in Claritin—may not be safe for people with severe liver conditions. The liver has to break down loratadine. The kidneys break down cetirizine—found in Zyrtec—and the body excretes it in the urine, largely unchanged. Claritin is more likely to interact with other drugs than Zyrtec.
Official answer. Yes, most people can take antihistamines every day, if they have daily symptoms of their allergies.
Fexofenadine use is not generally associated with liver enzyme elevations but terfenadine, a second generation antihistamine that is metabolized in part to fexofenadine, was the attributed cause of several reported cases of clinically apparent liver injury.
The liver then produces and stores allergy-specific antibodies called immunoglobulins. These antibodies set off a reaction, and the release of too many inflammatory chemicals or hormones called histamines causes an allergic reaction, with a host of physical symptoms.
Too Much Alcohol
Alcoholic fatty liver, which causes liver inflammation (alcoholic hepatitis), eventual scarring (cirrhosis) and even liver cancer, is a process that begins on as little as four drinks a day for men and two for women. By the time you show symptoms, your liver may be damaged beyond repair.
Patients with renal and/or liver disease may be at greater risk for adverse effects from loratadine due to drug and metabolite accumulation. The manufacturer recommends one-half the regular dosage initially in patients with liver failure or decreased renal function (GFR < 30 mL/min).
Cetirizine (applies to Zyrtec) renal/liver disease
Cetirizine is eliminated primarily by the kidney but also undergoes metabolism in the liver to some extent. Patients with renal and/or liver disease may be at greater risk for adverse effects from cetirizine due to decreased drug clearance.
Severe liver failure and cholestatic and hypersensitivity hepatitis induced by antihistamines such as cyproheptadine, loratadine and terfenadin have been reported previously [2,3]. Increases of alanine aminotransferase (ALT) [2], hepatitis [4–8], and cholestasis [9–11] due to cetirizine use have been also reported.
These common side effects include sedation, impaired motor function, dizziness, dry mouth and throat, blurred vision, urinary retention and constipation. Antihistamines can worsen urinary retention and narrow angle glaucoma. The antihistamines rarely cause liver injury.
People who take antihistamines regularly may build up a tolerance to the drug, which means they need to take higher and higher doses to get the same effect. This can lead to addiction. Antihistamines are often addictive because they work by blocking histamine receptors.
As well as sedation, overdose often presents with anticholinergic symptoms (see Anticholinergic Syndrome). At higher doses, they can also cause sodium channel blockade with subsequent cardiovascular effects including QT prolongations and Torsades de Pointes.