I am pretty sure it wasn't an artery hit. When you hit an artery, the blood travels AWAY from the heart. OP, you were saying the burning sensation traveled UP your leg, which is TOWARDS your heart. Have you been using the veins in your foot a lot before this? Like I mentioned above, like you, shooting suboxone films has messed up all of my arm and hand veins, so I had to find somewhere else to go. So I did some research about IV'ing into your legs and feet. I had already shot into my feet many times before, but I hated it cuz the veins tend to roll, and just poking yourself down there hurts like a motherfuck. I tend to avoid the feet. Lol. Anyway, while researching leg and foot veins, I found the Great Saphenous Vein that travels from your inner groin/thigh area down the very inner knee, and down the inner side of your calf. I decided to try it. I registered successfully, and injected. It felt just fine as I was sitting down, but when I stood up to go, it felt like I strained/pulled my groin muscle. At first I didn't think it was from the shot, because everything else went fine. The bupe had it's usual IV effects, so I knew it was a successful hit. I just thought I strained my groin from standing up funny. That soon got proven wrong when I shot in there again later on. This time the pain was stiffer and more pronounced. I am pretty sure that the sub film just has some inactive caustic ingredients/substances in it that will irritate fresh blood vessels that never had foreign substances injected directly into them. It's weird though because just recently I had injected a fentanyl solution into that same vein, and didn't notice that burning sensation. So I am pretty sure it was just the suboxone films inactives that were the culprits inducing the sensation.
What else I was saying is I am pretty sure (BUT NOT 100% SURE) you didn't hit an artery. I had once accidentally injected a ~1.5mg piece of a suboxone strip directly into my radial artery once. I don't think I ever injected into an artery before this, but when it happened, I KNEW IMMEDIATELY WHAT IT WAS. Since most, if not all, of my regular veins at the crook of the elbow, and all the other ones in the upper area of my forearm/elbow are shot or just scared tissues so bad they are inaccessible, I decided to look further down my forearm towards the wrists, I found what looked like a good vessel. I didn't think of, or didn't know any better, that arteries have a pulse, since the heart pumps blood out through them, dispersing blood throughout your body to your extremities. I proceeded to attempt registering nonetheless. I don't know if it was the lighting in that bathroom, or if the color of the cloudy suboxone solution that covered up the look of the arterial blood. If I recall correctly, the blood that came gushing into the syringe didn't seem to appear as that BRIGHT RED AND FOAMY BLOOD, that they say arterial resembles when registering, but the blood DID COME IN WITH A LOT MORE PRESSURE AND FORCE, rather than a normal venous register. VENOUS BLOOD REGISTERS DARK IN COLOR, SLOWLY, AND WITH LOW PRESSURE. I proceeded to inject, despite the warning sign of how fast the blood ran in, and the high pressure , it kind of put resistance on the plunger as I was pushing it down.
After injecting, I IMMEDIATELY noticed things were not right. Right after injecting it felt like my hand was ON FIRE. I ALSO NOTICED WHITE SPOTS BROKE OUT DOWN THE REST OF MY FOREARM, WRIST, AND HAND. I ALSO GOT A VERY INTENSE SHARP PAIN IN THE JOINTS OF MY THUMB. Kind of like someone took my thumb, twisted it, then stabbed a knife through it. Man, it hurt so bad! MY THUMB AND INDEX FINGER ALSO SWELLED UP IMMENSELY TO WHERE I COULDNT BEND THEM FOR A FEW MINUTES. I ALSO CAME DOWN IN A RUSH OF A SEVERE PANIC ATTACK. Frantically, I logged onto BlueLight, and was able to confirm I had indeed injected into an artery. I found that all sources and information I read pointed to going to the ER IMMEDIATELY. I read about how arterial injections, especially when injecting PILLS, can lead to SERIOUS COMPLICATIONS, SUCH AS GANGRENE FROM CLOGGED CAPILLARIES. When injecting into an artery, the substance travels into smaller and smaller blood vessels. Any particles that were not dissolved all the way and were not water soluble, can get lodged and clog up those cappilaries, and basically the oxygenated, rich blood cannot flow right to where it needs to go, then necrotizes and dies. This is GANGRENE.
Worried as fuck, I went downstairs and told my friend about it and asked if he could run me to the ER. He wouldn't do it!! Some friend Huh? He just said that I would be fine, and that it had happened to him before, and he wound up fine. This would have comforted me, but I didn't inject heroin like he did this time. It was a sub strip piece, and I tried explaining to him that it may have different ingredients inside it that could cause serious problems, but he wasn't convinced it was an emergency. I contemplated calling 911, but I didn't want to have an ambulance at the house with his mom due home very soon. I would have wound up homeless in the street if she had showed up during it and found out what I was doing. So figuring I was stuck, I thought I would just put a warm compress on and off throughout the night, and just read up on it for a while. The swelling had subsided considerably, and there wasn't much pain anymore.
I stayed up for a few hours reading up on arterial injection and the complications and dangers. I read that even though most of the swelling and the pain subsided, I wasn't out of the woods quite yet. I found that it can actually take a while after the initial injection for gangrene to start to set in. This worried me and I was going to the ER ASAP.
The next morning pretty much all of the swelling and initial pain was gone, but I did notice some pretty bad stiffness in the area of my thumb, through the arch up into my index finger. It hurt like fuck, I had a hard time holding things, and trouble just making normal movement of my thumb and index finger.
With this stuff present, I decided to visit the ER. They took my blood, looked for infection, and evidence of blood clotting. They found none, and decided to discharge me. They just explained that IV'ing suboxone can be caustic to your blood vessels. They also told me to come back IMMEDIATELY if I noticed any changes, especially if I noticed things changing colors. Nothing ended up happening, I just dealt with that stiffness for a couple weeks.
This was about 6 months ago, and it seems to be fully functional again. If I look closely at the injection site, I can still see faint bluish black marks, where I think there was damaged capillaries, but it seems like it is benign.
Sorry for such a long post everyone, I just wanted anyone reading this to know what happens when injecting sub films into an artery. I still remember that pain like it was yesterday, or 5mins ago even. Never something I want to experience again.
Now every time I go to inject into a new blood vessel, I take the steps to make sure the place in question is not an artery. I feel for a pulse, if there's a pulse I won't inject anywhere near it, I pay attention to the texture, color, and the speed/pressure the blood comes in when registering. I haven't had that kind of problem since. I practice good IV technique.
For the OP, if something like this seriously worries you, Just go to the hospital, and be honest with them. IV/arterial complications can be literally life and limb threatening, especially when put off for too long.