"Relax, go to it." joke

Told to me by my mother, who owned a pharmacy in Tennessee, in 1950.
A fellow with a bad cough comes in to the pharmacy, walks up to
the counter and asks for the pharmacist. A young clerk tells him
that the pharmacist is not available. The man asks the young
clerk if he can recommend anything for his cough.
The clerk gives him a bottle of some medicine for his cough.
The customer takes a big swig, then after a few minutes, with
no apparent relief, he takes another, and another.
In a short while, the pharmacist returns, and sees his old friend,
the customer with the cough, sitting quietly in a booth
near the soda fountain. He says to his clerk that the fellow
has never before stopped at the soda fountain.
The clerk proudly tells the pharmacist the story of his transaction.
The pharmacist looks at the recommended medication and angrily
reprimands the clerk for recommending a laxative, instead of cough syrup.
The clerk reminds the pharmacist the whatever the mode, the medication
was effective. The pharmacist replies, "Now, he's afraid to cough!"