Doctor in the House S08E03 - Money Spasms

Duncan is shocked to find himself overdrawn at the bank, thanks to Dick's 'borrowing' his credit card to gamble on the horses. He lost and, as Andy MacKenzie is also in need of funds, the three doctors volunteer to be paid guinea pigs at a scientific research unit. This involves testing a new muscle relaxant, with which they are injected. Being so relaxed has dire results when they return to work at St. Swithins.