A urine test to measure pheniramine levels may be ordered in specific situations, such as:To monitor the effectiveness of pheniramine therapy in a patient who has been prescribed the medication for an allergic reaction or other conditionTo check for pheniramine toxicity in a patient who is taking high doses of the medication or has accidentally ingested an overdoseTo help diagnose a potential pheniramine overdose in a patient who presents with symptoms such as dizziness, confusion, and decreased breathing