Sorry to here your predicament.
Yes, yes, yes you can take those and you should be fine for at least a day. Luckily,
methadone lasts a very long time in your system, ie it has a very slow metabolism. I know this because a good friend of mine switched from
hydrocodone to
oxycodone instant release. He was started on 15mg 4 times a day but was waking up in the night feeling like ********************. He has a VERY fast metabolism; thus, it went thru his system quickly and his body needed more thru the night. His Dr offered methadone because it lasted much longer. Oh, and it should still work as long as it hasnt been in direct sun light for a period of time. Start by taking 1 and see if you can get by the entire day. Hope that helps.
One more thing, research Kratom. Its a plant made into powder that reacts similar to opiates by attaching to the opiate receptors. It has saved me a couple of times(I take hydro as well). I get it from
www.iamshaman.com which has the best prices and best quality. AND it is legal.