Brief Answer:
Needs a consult and management

Detailed Answer:
Thank you for asking
The two drugs you mention are telmisartan and to rosuvastatin and none of them cause dry mouth. Sleep apnea itself is a major cause of dry mouth or xerostomia. It needs a little work up and consult to your doctor to sort out the cause of dry mouth in your case.

Your BMI is roughly 32 and lies in obesity category and needs to be addressed. Obesity itself can trigger dry mouth and sleep apnea.in nutshell your troubles of obesity, sleep apnea and dry mouth seem connected and need to be dug a little further for surety.
Here are some of the general measures for dry mouth management.

-regular sips frequently up to 2 litres of water a day minimum to keep mouth hydrated.
- Avoiding the medicines and where not possible replacement with some less xerostomic drugs, consulting with your urologist will help.
-avoid irritants such as smoking, alcohol and caffeine intake.
-keep good oral hygiene, treat oral candidiasis or caries precautions to stay safe as dry mouth predisposes to oral troubles, stay in touch with the dentist for further oral management.
-Anxiety and stress should be avoided as they themselves are causative agents.
-Try some salivary substitutes as Artificial saliva can provide relief of dry mouth. They are manufactured with a neutral pH and contain electrolytes that approximately correspond to normal saliva. They are either mucin or methycellulose based preparations. The mucin based products are better tolerated and have a longer duration of action. Preparations are available in the form of sprays, gel and lozenges.
-Mouth washes with garlic water etc.
-Try salivary stimulants , here are some
a-Chewing Gum
Sugar free chewing gum increases and promotes salivary flow by stimulating taste receptors, and its use is usually not associated with side effects. A combination of regular mouthwash and chewing gum is proved helpful.
b-Ascorbic Acid (Vitamin C)
Vitamin C tablets are used to treat xerostomia/ dry mouth  in palliative care. In a study, the effectiveness of ascorbic acid was compared against artificial saliva and other stimulants in patients with xerostomia. Vitamin C was shown to be subjectively more effective than artificial saliva, but less effective than other salivary stimulants. The main disadvantage of using ascorbic acid long term is its detrimental effect on teeth enamel.
c-Malic Acid
Malic acid is effective in the treatment of xerostomia and is naturally found in fruits such as pears and apples. Its main disadvantage is that it causes demineralisation of teeth enamel, which limits its long-term use.
d-Pilocarpine
Pilocarpine is a muscarinic receptor agonist and has been shown to improve symptoms of xerostomia.It is available as 5 mg tablets and can be administered up to a maximum dose of 30 mg/day in divided doses. The effects of Pilocarpine are usually immediate; The increase in saliva production generally lasts for 4 h. Its undesirable side effects include perspiration, flushing, lacrimation, urinary frequency and gastrointestinal disturbances. As a result of its cholinergic effect, it is contraindicated in patients with asthma, chronic obstructive airway disease, heart diseases, epilepsy, hyperthyroidism and Parkinson’s disease..
e-Other Parasympathomimetic Drugs
carbachol. pyridostigmine,Cevimeline etc are proved helpful.
f-Radiprotectants
Cytoprotective agents such as amifostine have shown to minimise tissue damage secondary to radiotherapy and decrease the incidence of radiation-induced xerostomia
g-Acupuncture
Acupuncture as a treatment for xerostomia is increasingly being recognised in the West. In a study from Sweden, subjects who received traditional acupuncture demonstrated a significant increase in salivary flow rate lasting up to a year as opposed to those in the placebo group
I hope it helps. Take good care of yourself and don't forget to close the discussion please.
May the odds be ever in your favour.
Regards
Khan

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