Based on the information provided, I was unable to find specific data regarding side effects when Sapropterin eliminated symptoms entirely. However, I can provide some context about Sapropterin and its potential side effects.

Sapropterin, also known as Kuvan, is a prescription medication used to reduce elevated blood levels of phenylalanine (Phe) in patients with a certain genetic disorder called phenylketonuria (PKU) [1]. PKU is a metabolic disorder that makes it difficult for the body to break down Phe, an amino acid found in proteins [1].

Common side effects of Sapropterin include headache, runny or stuffy nose, diarrhea, vomiting, and cough [1]. It is essential to note that the drug's side effects may vary from person to person, and some individuals might not experience any adverse reactions [1].

In some cases, Sapropterin has been reported to eliminate PKU symptoms entirely [2]. However, there is no direct information available on side effects specifically related to the elimination of symptoms. It is possible that patients who experience the elimination of symptoms might still encounter side effects unrelated to the resolution of their PKU symptoms.

In conclusion, while there is no specific information on side effects when Sapropterin eliminates symptoms entirely, it is crucial for patients to be aware of potential side effects and monitor their health closely while taking this medication.

Sources:
[1] U.S. Food and Drug Administration. (2018). KUVAN (sapropterin dihydrochloride) tablets for oral use. Retrieved from https://www.fda.gov/media/78938/download
[2] DrugPatentWatch.com. (n.d.). Kuvan (sapropterin dihydrochloride). Retrieved from https://www.drugpatentwatch.com/drugs/kuvan