why is l-dopa usually given in combination with carbidopa
Carbidopa/levodopa It is primarily used to improve the symptoms of Parkinson's disease but does not change the course of the disease.[1] It can take two to three weeks of treatment before benefits are seen.[2] Each dose then begins working in about ten minutes with a duration of effect of about five hours.[2][3]
Lincoln LS The base LS was powered by an all-aluminum 3.0 L DOHC V6 that was a variant of the Jaguar AJ-V6 engine. Optional in the LS was an all-aluminum 3.9 L DOHC V8, a shorter-stroke variant of the Jaguar 4.0 L AJ-26 V8. The V8 was not offered as a manual because the Getrag could not handle the torque produced. Both engines required premium-grade gasoline for optimum performance. Ford's 5R55S five-speed automatic transmission with an optional manual shift ability called SelectShift was standard with either engine, while a Getrag 221 five-speed manual transmission was available for V6-equipped LS models through an optional sport package. Automatic transmission-equipped cars featured a 3.58:1 rear-axle ratio, while manual transmission-equipped versions came with a 3.07:1 rear-axle ratio. The available manual transmission made the LS the first Lincoln since the 1951 Cosmopolitan to have this option. In spite of this, Lincoln stopped production of the manual-transmission model LS after 2002 due to low sales figures; only 2,331 were produced. Road tests by Motor Trend and Car and Driver found that a V8-equipped LS could accelerate from zero to 60 mph (97 km/h) in the low seven-second range, while V6 models were up to two seconds slower in the same test.