what did Germ put into Zachs drink?

Perhaps you can be more specific? The link confirms that it's life-threatening when ingested. People have been arrested for trying to poison someone using it. That's pretty much all Lightning said. I'm not sure what you are disputing.

From the link: If taken internally, however, this drug acts like a potent high blood pressure medicine. Symptoms reported in both children and adults who have swallowed some of these eye care products either by accident or via malicious activity include marked drowsiness, low blood pressure, slowed heart rate, and possibly even coma and impaired breathing. Quantities as low as ½ to 1½ teaspoonfuls (approximately 1/6 to ½ of a half ounce bottle) have caused pronounced reactions in small children. Toxic affects following tetrahydrozoline ingestion can be serious and at times require close observation and treatment in an intensive care setting. Fortunately, no deaths have been reported.

And, here's another link for you. http://www.snopes.com/medical/myths/visine.asp