Prolonged use of some antihistamines can also lead to other rare side effects such as dry mouth, drowsiness, and blurred vision. Overall, antihistamines are generally safe and effective for managing allergic conditions but prolonged use can have some risks.
It's generally safe to take the newer generation of antihistamines daily if you have year-round allergy symptoms. But make sure to avoid anything that has a "D" in its brand name, which stands for decongestants. Long-term use of decongestants will worsen your allergy symptoms.
In general, most of the available over-the-counter antihistamines are safe for long-term use. There are some potential side effects and there are some cases where long-term antihistamine use can worsen urinary retention or narrow angle glaucoma.
Like Benadryl and Zyrtec, some antihistamines are safe to take over the long term. In these cases, people can continue taking their medications as prescribed.
Answer: Yes, it is ok to take the medication for an extended period of time. However, the "D" formulation has a decongestant (which is what the 'D' represents in the name) and this can raise your blood pressure. I would recommend discussing with your doctor if this will be a possible problem for you.
Cetirizine is unlikely to do you any harm if you take it for a long time. However it's best to take cetirizine only for as long as you need to. If you take it regularly over a long period there's a very small chance of severe itching if you stop treatment suddenly.
"When taken in the recommended doses, antihistamines can be taken daily.
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®).
Anticholinergic and alpha-adrenergic side effects
Many over-the-counter antihistamines contain a decongestant as well, and therefore if the user experiences palpitations, the medication should be stopped.
The evidence presented does suggest, however, that patients on prolonged antihistamine therapy may develop clinical tolerance. When this is suspected the dose should be increased or the drug discontinued for a short perior (3 to 14 days) before resuming therapy.
When an allergy medication doesn't work anymore—either as well as before or at all—it could be because your body is no longer reacting to the drug in the same way it once did or is clearing it too quickly for it to be effective. This is known as a drug tolerance. This can happen after months and years of use.
When antihistamines block histamine, our appetite can increase. This, plus side effects like drowsiness, could lead to weight gain. Your risk of gaining weight from antihistamines may depend on many factors. But a healthy diet, physical activity, and other lifestyle factors can help you manage your risk.
In general, wean gradually by 25-50% of the daily dose every 1-4 weeks. If reason for deprescribing is serious adverse effects, wean faster or cease immediately.
Lesser sedating antihistamines
In overdose symptoms can include dizziness, tachycardia, headache drowsiness or agitation.
Long-term use can cause cataracts, osteoporosis, muscle weakness, stomach ulcers, increased blood sugar (glucose) and delayed growth in children. Oral corticosteroids can also worsen high blood pressure. Prescription oral corticosteroids include: Prednisolone (Prelone)
In some patients, antihistamines stop working after months or even years of use. Sadly, the people who most experience the most reduced benefit often suffer from chronic and severe allergy symptoms.
Zyrtec Withdrawal: Severe Itching & Hives
This itching may begin as soon as 12 hours after the last dose of Zyrtec and can affect every part of the body. Some patients report itching so severe that they cannot control scratching and have caused sores all over their bodies.
What is the most powerful natural antihistamine? Researchers haven't yet established any natural product as the “best” or “most powerful.” Natural antihistamines with the most research backing their use include stinging nettle, vitamin C, quercetin, butterbur, bromelain, and probiotics.
Sandoz issued a voluntary recall of 1,023,430 units of Zyrtec (10 mg) capsules as a result of failed impurities and a specification being reported for impurity at the 21-month stability time point, according to an FDA Enforcement Report.
If you're someone for whom the benefits of regular antihistamine use far outweighs the occasional minor side effect, longterm use is safe for most adults and children, he adds. All that said: over-the-counter medication is still medication, and should be treated accordingly.
Antihistamines can also make you feel tired and unmotivated to exercise. Antihistamines that can cause weight gain include: Diphenhydramine (Benadryl and others) Cetirizine (Zyrtec)
Overdose Signs
Overdose symptoms may include severe drowsiness, vision problems, agitation, fast heartbeats, stomach pain, nausea, vomiting, trouble walking, trouble swallowing or speaking.
Common medications like Zyrtec, Allegra, Flonase, and Claritin don't usually stop working. It's time to check for new allergies if your nose is still stuffy and you can't stop sneezing after taking your regular allergy medicine. You may need a new treatment plan, not just more medication.
People with allergies may find relief by using natural plant extracts and foods that act as antihistamines. Examples include vitamin C, butterbur, and probiotics, but there are many possible options.
See your doctor if your mild allergy symptoms have not improved after three days of treatment with Zyrtec, or if your hives persist for more than six weeks despite taking Zyrtec. Discontinue Zyrtec once your allergy symptoms have resolved.