Brief Answer:
Significant weight loss, needs work up

Detailed Answer:
Thank you for asking
Adavin is an anxiolytic and i don't think mere anxiety can cause so much weight loss. This is called significant weight loss and it needs work up to sort out and rule out any harmful etiologies.
PEG percutaneous endoscopic gastrostomies lines are also notorious for weight imbalances and can be considered a cause here but it needs work up to confirm.

below is the long list of possibilities for such a significatn weight loss and they need to be addressed before it is too late.

Loss of appetite and conditions that prevent food consumption, eg dysphagia, painful mouth sores, newly applied orthodontic appliances, or loss of teeth.
Persistent vomiting, eg pyloric stenosis, hiatus hernia.
Malabsorption, eg coeliac disease, chronic pancreatitis, Crohn's disease, gastrointestinal infection, gastrointestinal fistulas, carcinoid, intestinal hypermotility, hepatobiliary disease, food intolerance.
Medication, especially polypharmacy in the elderly.
Endocrine: diabetes mellitus, hyperthyroidism, Addison's disease, gut hormone tumours (eg VIPoma).
Malignancy: lymphoma, leukaemia, carcinoma, sarcoma.
Systemic disease, eg heart failure, chronic respiratory disease, chronic renal failure, liver failure, rheumatoid arthritis, systemic lupus erythematosus.
Acute infection.
Chronic infections and infestations, eg tuberculosis, HIV (one in ten in one study),[2] parasitic infections.
Drug abuse, heavy smoking.
Malnutrition, social isolation.
Psychological: stressful life events, depression, anorexia nervosa, psychoses, manipulative behaviour, food phobias.

Nut shell, get to an internal medicine expert and let them connect the dots and make a complete clinical correlation for further management.

I hope it helps. take good care of your wife and do as directed. Dont forget to close the discussion please.

May the odds be ever in your favour.
regards
Khan

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