SIDER Get Drugs For Side Effect

Find all drugs associated with a specific side effect in SIDER. Returns drugs known to cause the given adverse reaction, with frequency information when available (e.g., '7%', '5% - 18%', 'postmarketing', 'common'). Provide either a MedDRA code (e.g., C0018681 for headache) or a side effect name (will auto-search). Useful for drug safety comparisons and adverse event analysis.