Questions and Answers
The sole use for pilocarpine is to decrease intraocular pressure in the management of glaucoma. I'll assume this is the case. It is most often applied as eye drops. Its duration of action is 4 - 6 hours so has to be applied several times a day indefinitely. There is available an intraocular preparation, Ocusert, which lasts much longer and, hence, is easier to use (better compliance), and reduces the total amount of drug administered over any particular interval. In neither case are systemic effects normally seen on ocular administration. If they do occur, the following will be seen - increased production of saliva, sweat and tears, followed by nausea, profuse vomiting and diarrhoea. Pulmonary oedema and symptoms of shock may accompany these.
Zestril (lisinopril) is a so-called ACE inhibitor, widely used as the sole drug in the treatment of hypertension. I have no record of an interaction with pilocarpine used as above. In itself it is not without side-effects. The most common are - dizziness, headache, weakness, chest pain, nausea and vomiting, a cough, and a rash. I haven't seen any report of pulmonary oedema.
From the above, the only, but very unlikely, suspect might be the pilocarpine. The only way to prove its involvement would be to stop this treatment and substitute another ( for all glaucomas that respond to pilocarpine, there are alternative treatments ).
I wonder if your husband has been examined by a cardiologist for the presence of congestive heart failure - this condition in the form of pulmonary venous hypertension gives rise to pulmonary oedema. Lisinopril may be used to treat it, but may require a different dosage than he is currently using. Just a thought.
Best wishes to you and your husband.