Dear patient, abnormal taste sensation like the taste of rubber bands or metalic taste is called dysgeusia. It can be due to multiple reasons like 1. Asthama treatment with albuterol , may be your sister is using it for COPD 2.Dental and oral cavity conditions like gum disease, dental plaques , dry mouth (xerostomia) due to any cause ,poor oral hygiene, mucositis and oral ulcers 3. Gastric acid reflux disease 4. Ear disease involving chorda tympani nerve which is responsible for carrying taste sensation 5. Any lession in the nerves involved in taste pathway 6.Systemic diseases like diabetes, hypothyroidism and cancer 7. Drugs like chemotherpeutic agents for cancer, antihypertensive medications , antihistaminics, diuretic, or antibiotics 8. Zinc deficiency So in case of your sister some causes are obeviously present there like diabetes, acid reflux disease, may be receiving albuterol for COPD, but still i will suggest you to get an orodental, ENT ,check up done to rule out other relevant causes as mentioned above. Also get thyroid function test done as your sister is having truncal obesity, a reveiw of the medicines which she is receiving by a physian to see if there is any offending drug that is causind this problem . Finalley she can also take zinc suppliment and antioxidant called alpha lipoic acid which has been found to be beneficial in this condition and also use artificial saliva. Her acid reflux disease needs to be properly controlled by pantaprazole-domperidone tablet once or twice daily 1 hour before meals