I'm taking 100mg of benzonatate 3x's day /4, days now have had cough for 10days. Can I take a double does for bed so I can sleep. I am waken from cough?

Ask prescribing doc. Please check with your physician to confirm this is acceptable to him or her--without knowing if you have other health conditions or what exactly you are dealing with now, it would not be wise to tell you to take anything other than the prescribed dose. I will say that the maximum daily dose of Benzonatate is 600mg, and it is often prescribed in the 100mg or 200mg capsules.