Welcome to HCM! After reading your question carefully I found that you have spells of dizziness usually in lying down position, every few months. It would have been more helpful if you would have mentioned your age, if you have any other illness like BP, diabetes, arthritis or thyroid. I don t think you have ever got it checked and got any investigations done for the same? Had I been treating you, I would like to go for x Ray neck AP and Lateral view, along with an MRI. Brain. These featus resemble cervical spondylosis which can cause dizziness. In your case the problem should be of milder nature as the spells of dizziness happen in months and rest of time you keep ok. these symptoms can also occur sometimes in case of low heamoglobin and low blood pressure, so by getting it checked one can rule this out. So, to nip the problem in the bud, please go and get your self investigated as dizziness is a symptoms due to some cause and it should be taken care of. Taking Semitil is not going to cure your illness but only subside it temporarily. Hope the reply is helpful to you Feel free to ask more questions