Yes, your medications specifically the tricyclic antidepressant (dosulepin) and calcium channel blocker (flunarizine) components commonly cause constipation. This straining can certainly worsen your piles. Since your dizziness is not improving, please consult your doctor before making changes. They can safely adjust your doses or switch you to alternative treatments with fewer digestive side effects, such as alternative migraine preventatives or vestibular physical therapy. For immediate relief from constipation, increase your water and fiber intake, and ask your doctor about a safe stool softener. Do not stop your current medications abruptly.