What you're describing sounds like orthostatic hypotension — a drop in blood pressure when you change positions (sitting to standing, lying to sitting). There are several reasons this can occur after a dose increase:
- Dehydration — the most common cause. Reduced food intake means less water from food, and many patients don't compensate with additional fluids. Even mild dehydration drops your blood volume and blood pressure.
- Reduced caloric intake — eating less at the higher dose means lower insulin secretion and potentially lower blood sugar, both of which can cause lightheadedness.
- Blood pressure reduction — GLP-1 RAs can lower blood pressure by 2-6 mmHg on average. If you're already on antihypertensives, the combined effect may be too much.
Immediate recommendations:
- Check your blood pressure at home if you have a cuff, especially lying down vs. standing
- Increase fluid intake significantly — 80-100 oz/day, with electrolytes
- Rise slowly — sit on the bed for 30 seconds before standing, stand for 30 seconds before walking
- Make sure you're eating enough — don't skip meals even if not hungry
- If you're on blood pressure medications, contact your prescriber — you may need a dose adjustment
If the dizziness is severe, persistent, or accompanied by fainting, heart palpitations, or chest pain, seek medical evaluation today.