Keytruda for melonoma. Extremely stiffness?

@jaxthecat Welcome to Mayo Clinic Connect. I’m sorry to hear you’ve been experiencing these side effects. I’ve also been on Keytruda for metastatic melanoma and have encountered some adverse reactions to various extents although not this particular one. There are potentially quite a few as listed here, so to encounter one, two or more is regrettably not unusual: https://www.mayoclinic.org/drugs-supplements/pembrolizumab-intravenous-route/description/drg-20122552. In my case, they’ve been tempered by the fact that the immunotherapy has been successful.

In most cases, the adverse effects tend to subside but during a flare they can be quite troublesome. It sounds like you’re taking the proper steps to treat, among them using heat or cold packs, gentle stretching, and over-the-counter pain relievers like acetaminophen or ibuprofen. If these become ineffective or your symptoms worsen, talk to your provider who may consider stronger meds or corticosteroids.

Can you circle back in a few weeks to let me know how you’re doing?

I'm taking a drug in the same class for basal cell carcinoma and have bouts of stiffness, also in my hips and legs. They come and go as do muscle cramps and spasms. Some spasms are quite painful and disruptive to sleep.

What's helping me:
Massages, self massage with vibrator
Exercise - there's a 'sweet spot'
Electrolyte supplements (sodium, chloride, magnesium, potassium, calcium) TALK TO YOUR DOCTOR FIRST
Tizanidine 4mg 3x/day
Cold (freezing bedroom at night seems to help sleep)
Stretching and changing positions frequently

Good luck, I hope your symptoms and melanoma improve! ❣️