Try setting it at 3. Sometimes the highest (lower Temp) creates a problem..same with the A/C unit. I have found the mid range settings to work the best.
Fans at the rear of the fridge will help.
Make sure you have an accurate thermometer to measure the temp. Temp will vary throughout the day as the sun heats up the side where the fridge is.
We have a side by side Dometic and the temp usually stays around 35-38 but will go as high as 48 in 80 plus heat with the sun shining on the sidewall where the fridge is located. Ours is vented through the roof with no fans.
Our coolest shelf is the top one in the fridge. The bottom and door shelves are the warmest area. So try moving the thermometer around to find the coolest spot for the meds.
You could add dry ice in a container near the meds in the fridge to help keep the meds cooler.