Singulair is a drug which comes from the class of leukotriene recptor antagonists. The use of Singulair for capsular contracture is based on anecdotal reports of improvement (softening) of capsular contracture in individuals undergoing treatment with Accolate, another drug in this class. Accolate is prescribed twice a day. The advantage of Singulair is its once-a-day dosing and relatively high safety profile. It is one of the most popular pediatric asthma medications.
The initial reports coming from Hawaii claimed that it was most beneficial if patients were treated within 6 monhts of surgery.
There is some logic in the use of these meds becasuse they block the inflammatory effects and constriction effects of leukotrienes in asthmatic individuals. The obvious thought was that maybe they could minimize the bodies' inflammatory responses and contraction of tissues surrounding breast implants. However, true data and studies validating their use are lacking. Although generally safe, they do require monitoring and occasional blood work.
I have had patient's treated with both this and Accolate. Although some physicians report as hgih as an 80% response rate, I would place my response rate at 50%. Therefore, I am not an enthusiatic proponent of this therapy.
To answer your second question: Yes, it is likely that the capsular contracture is "holding up" your implant and preventing it from descending. It is still relatively early after your surgery and you should perform preferential breast implant displacement exercises if cleared by your plastic surgeon.
I hope this helps to explain.