Muscle Weakness & Pain After Taking Colistin With Magenx Forte. Being Treated For Multidrug Resistant Klebsiella Pneumoniae. Different Medication?

The patient has a neurogenic bladder due to a spinal cord injury (5 years back), she is on indwelling catheter since. A month back The patient was diagnosed with pseudomonas aeruginosa infection after heavy fever and was admitted for 5 days. She was treated with Magnex Forte and paracetamol. At the time of discharge the fever and infection went away and Magnex forte 3g (twice daily) was recommended for 14 days. After 14 days, urine culture was repeated again and multi drug resistant klebsiella pneumoniae infection is identified. The bacteria was only sensitive to colistin and tigecycline. However, the patient is asymptomatic(no fever,chills). The doctor recommended colistin (3 million iu twice daily) with Magenx forte (3g twice daily). After first day of dosage, the patient felt weakness with mild headache and difficulty to move due to muscle pain. When asked, the doctor said this is unusual and instructed to stop the medication. Is the symptoms of weakness normal looking at the dosage? Is there any recommended medication for the weakness ? Is is ok to stop the medication prematurely ? If we stop the medication what s the next step to eliminate the infection ?