Hi!
Well yes, Losartan can cause hair fall and alopecia. If so, then stopping the drug should stop the hair fall. You can discuss with your doctor and start an alternative drug, but please do not stop drugs on your own.
If the hair fall persists, then other causes will need to be looked into. Iron deficiency is the commonest cause of hair loss. Iron deficiency can be due to poor intake or poor absorption or due to hidden loss from bleeding as is seen in UTI and gut problems like IBS. The cause of anemia has to be found out by various blood tests. Iron replacement along with diet rich in iron and hemoglobin should be given. Please consult a hematologist if iron deficiency is detected. Hair loss can also be due to dandruff, dermatitis, shampoos, oils, soaps, dust and dirt etc. Thyroid disorders and diabetes too could be a cause. Insomnia, stress and anxiety along with poor diet and excess of caffeine too can be the cause. Please consult your PCP for primary examination. Take care!