Brief Answer:
Needs work up and management, Infection of airways? Oral hygiene.

Detailed Answer:
Thank you for asking

I read your question and i understand your concern. With history of inhaler use bad breath could likely be attributed to inhaler induced oral hygiene compromise and likely oral candidiasis but with no white spots in mouth that is likely a preliminary stage and can easily be managed with a few doses of oral antifungals drops and regular mouthwash after every inhaling puff.

Other possibilities of bad taste are acid reflux of stomach, dental caries or infection, upper respiratory tract infection ( likely possible because of the sputum color as well) . You will need a little work up like chest X ray and sputum analysis to rule out active infection. If you have fever or bad chest talk to your doctor immedietly and let them rule out airways infection as it is ommon in old age and more common in old age with inhaler use.

Meanwhile try following home remedies for bad taste.
-Gargle with water.
-Brush your teeth, tongue, roof of your mouth, and gums using toothpaste.
-Rinse your mouth with mouthwash.
-Drink liquids, chew sugar-free gum or mints, or suck on sour candies.
-Use plastic utensils if you have a bitter or metallic taste when eating.

I hope it helps. Take good care of yourself and dont forget to close the discussion please.

Regards
Khan

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