Hello Sir/Mam, I understand your problem.Excess saliva is due to two reasons.actual excess production or inability to swallow it during sleep.when you are very tired or taking any drugs that cause drowsiness you might have less swallowing reflex during sleep.second one your salivary secretion itself is induced more from your glands due to many reasons .You can avoid sweets and high glucose diet at night time.Brushing and using mouthwash at night reduces the pasty nature of saliva.you will feel much better in the morning.Try this as firstline remedy.Then we can ruleout any infection or problem with salivary gland or duct. Hope your query is answered.please dont hesitate to contact me for further queries.