Hello, I have gone through your query and understand your concern. As you have said the vertigo after viral infection, probably she was suffered from Labrynthitis or Vestibular Neurronitis. It is possibly a Vestibular neuronitis. Because in Labrynthitis, vertigo or dizziness will go away once the infection is cleared. As she is having the vertigo for last 4 years, it is probably a vestibular neuronitis. Coming to your question. NO. There is no specific side effect on withdrawal of Meclizine( vertin). Thus she may stop the vertin, if she do not feel any vertigo symptoms as directed by your doctor. You have mentioned about thyroid problem and Hypertension. Please check the Thyroid profile and confirm whether it is hyper or hypothyroidism and advise her to take the drug properly. As she have hypertension, Antihypertensives are necessary and she should monitor her blood pressure regularly. There is no co- relation between stopping vertin and her Hypertension and thyroid problem. Hope this helps. Please write back for further queries. Wishing you good health.