This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Medicine
All are indicated in a patient with cystinuria with multiple renal stones except 
Select and explain. 
A. Cysteamine, B. Increase fluid intake, C. Alkalinization of urine, D. Penicillamine
A: Cysteamine
Answer: A: Cysteamine 
Explanation: Ans. a. Cysteamine Patient with cystinuria with multiple renal stones should be treated with increase urine volume (high fluid intake), alkalinization of urine Penicillamine and tiopronin. Cystinuria (AR) Inheritance: Autosomal recessive Molecular defect: Shared dibasic cystine transpoer SLC3A1, SLC7A9Q Tissue manifesting transpo defect: Proximal renal tubule, jejunal mucosaQ Individual substrate: COLA (Cystine, Ornithine, Lysine, Arginine)Q Clinical features: Cystine nephrolithiasisQ Treatment: Increase urine volumeQ (high fluid intake) Alkalinization of urineQ PenicillamineQ and tiopronin undergoes sulfhydryl-disulphide exchange with cystine to form mixed disulphides, since these disulphides are much soluble than cystine, pharmacologic therapy can prevent and promote dissolution of calculi