Protein helps preserve muscle; strength training is what tells your body to keep that muscle while you lose weight. Two to three sessions a week already make a difference. You do not need a gym full of machines: squats, push-ups, rows with weights, and planks at home count.
People who combine the medication with strength training lose far less muscle than people who only diet. Cardio is great for your heart, but strength training is what preserves lean mass.
Your workout plan here already reflects that focus when you say you use the medication. This information is here to help you understand what you are going through and does not replace your doctor. Your doctor is the one who adjusts the medication, the dose, and the treatment plan.
Based on: reviews on strength training and preserving lean mass during weight loss.